diff --git a/src/db_utils/interactions/features_interactions.py b/src/db_utils/interactions/features_interactions.py
index d6a5898502c10ee597c08bffde23fe31c4b7ac1b..bc0f819d522f49fdc14f101e1d7b9dbd50e9a98d 100644
--- a/src/db_utils/interactions/features_interactions.py
+++ b/src/db_utils/interactions/features_interactions.py
@@ -3,7 +3,7 @@
 # -*- coding: UTF-8 -*-
 
 """
-Description:This script allows to determine which couples of genomic regions
+Description: This script allows to determine which couples of genomic regions
 interact, e.g. exons or genes, that for each ChIA-PET dataset.
 
 This script requires the output file produced by the script bedtools.py, which
@@ -36,10 +36,11 @@ def work_on_pet():
     #chr1 start1 end1 chr1:start1..end1-chr2:start2..end2,weight1-2 weight1-2 .
     #chr2 start2 end2 chr1:start1..end1-chr2:start2..end2,weight1-2 weight1-2 .
     We want the following output format:
-    #chr1:start1..end1   chr2:start2..end2   weight1-2
-    10:100172432..100175026    6:92192672..92194172  2
+    #anchor1                    anchor2                 weight
+    #chr1:start1..end1          chr2:start2..end2       weight1-2
+    10:100172432..100175026     6:92192672..92194172    2
 
-    :return:
+    :return: Pet in this format: chr1:start1..end1 chr2:start2..end2 weight1-2
     """
     pet = pd.read_csv(Config.chia_pet / "GSM1517080.bed", sep="\t",
                       header=None)
@@ -52,12 +53,13 @@ def work_on_pet():
 def del_overlaps(pet: pd.DataFrame):
     """
     This works on the previous dataframe result (pet). Input format is:
-    #chr1:start1..end1   chr2:start2..end2   weight1-2
+    #anchor1                    anchor2                 weight
+    #chr1:start1..end1          chr2:start2..end2       weight1-2
     We delete from this dataframe the pet that has overlapping anchors, e.g.
-    9:139773532..139778733  9:139778161..139781850  7
+    9:139773532..139778733      9:139778161..139781850  7
 
-    :param pet:
-    :return:
+    :param pet: In this format: chr1:start1..end1 chr2:start2..end2 weight1-2
+    :return: Pet dataframe without pet that have overlapping anchors
     """
     pet[["chr1", "start1", "space1", "end1"]] = pet["anchor1"].str.\
         split(r"[:..]", expand=True)
@@ -90,12 +92,14 @@ def work_on_intersection():
     format is (see the description of this script for more information), e.g.
     18 28681 28882 1_1 0 - 18 28682 28782 1:47797..47799-18:28682..28782,2 2 .
     100
-    We want a dictionary linking the id of the pet to the region (exon/gene) \
-    it contains.
+    We return a dictionary which link the id of the pet with the region
+    (exon/gene) it contains, e.g. '17:73176122..73178842': ['19423_1',
+    '19423_2']
 
-    :return:
+    :return: A dictionary which link the id of the pet with the region
+    (exon/gene) it contains.
     """
-    inter_file = Config.pet_vs_gene_output / "gene_w200_vs_GSM1517080.bed"
+    inter_file = Config.pet_vs_exon_output / "exon_w200_vs_GSM1517080.bed"
     dic = {}
     with inter_file.open("r") as infile:
         for line in infile:
@@ -113,14 +117,17 @@ def interactions(pet: pd.DataFrame, anchor_dic: Dict[str, List[str]]):
     """
     Allows to determine which couples of genomic regions interact, according to
     what weight.
-    #id_region_a1    id_anchor_a1    id_region_a2    id_anchor_a2    weight
-    7832    10:10019900..10020058 16755   11:5834473..5834631   2
-    It means that gene 7832 interacts with gene 16755, according to a weight of
-    2.
-
-    :param pet:
-    :param anchor_dic:
-    :return:
+    #id_region_1 id_region_2  id_anchor_1       id_anchor_2       level  weight
+    9815_1       9815_7       1:858942..862596  1:874802..878017  intra  4
+    It means that exon 9815_1 interacts with exon 9815_7, according to a weight
+    of 4 and that the interaction is intrachromosome.
+
+    :param pet: del_overlaps() return = pet dataframe without pet that have
+    overlapping anchors.
+    :param anchor_dic: work_on_intersection() return = a dictionary which link
+    the id of the pet with the region (exon/gene) it contains.
+    :return: A dataframe with these columns: id_region_1, id_region_2,
+    id_anchor_1, id_anchor_2, level, weight
     """
     pet_dic = pet.to_dict("index")
     pbar = tqdm(pet_dic.keys())
@@ -139,17 +146,17 @@ def interactions(pet: pd.DataFrame, anchor_dic: Dict[str, List[str]]):
                 continue
             couples = np.c_[couples, [anchor1] * clen, [anchor2] * clen,
                             [get_level(anchor1, anchor2, pattern)] * clen]
-            couples_df = pd.DataFrame(couples, columns=["id_region_a1",
-                                                        "id_region_a2",
-                                                        "id_anchor_a1",
-                                                        "id_anchor_a2",
+            couples_df = pd.DataFrame(couples, columns=["id_region_1",
+                                                        "id_region_2",
+                                                        "id_anchor_1",
+                                                        "id_anchor_2",
                                                         "level"])
             couples_list.append(couples_df)
         except KeyError:
             continue
     df_final = pd.concat(couples_list, axis=0, ignore_index=True)
     df_final = df_final.merge(pet, how="left",
-                              left_on=["id_anchor_a1", "id_anchor_a2"],
+                              left_on=["id_anchor_1", "id_anchor_2"],
                               right_on=["anchor1", "anchor2"])
     df_final.drop(["anchor1", "anchor2"], axis=1, inplace=True)
     df_final.rename(columns={2: "weight"}, inplace=True)
@@ -158,7 +165,9 @@ def interactions(pet: pd.DataFrame, anchor_dic: Dict[str, List[str]]):
 
 def get_level(anchor1: str, anchor2: str, pattern: re.Pattern) -> str:
     """
-    Say if anchor1 and anchor2 are on the same chromosome.
+    Look if anchor_1 and anchor_2 (so also region_1 and region_2) are on the
+    same chromosome or not, so if the interaction is intrachromosome or
+    interchromosome.
 
     :param anchor1: The id of an anchor
     :param anchor2: The mate of anchor1
@@ -173,51 +182,57 @@ def get_level(anchor1: str, anchor2: str, pattern: re.Pattern) -> str:
 
 def filtering_1(region_lists: List) -> List:
     """
-    Removing common exons.
+    Remove pairs of interacting regions that would be the same, e.g.
+    #id_region_1    id_region_2    weight
+    9815_1    9815_1   2
 
     :param region_lists: List of couple of regions
-    :return: The lists without common regions
+    :return: Region_lists without pairs of interacting regions that would be
+    the same
     """
-
     return [sorted(couple) for couple in region_lists
             if couple[0] != couple[1]]
 
 
 def filtering_2(df_filter_2: pd.DataFrame):
     """
-    Filtering of the previous dataframe result (df_filter_1) by adding:
-    - the weights of the interactions that describe the same interaction, e.g.
-    #id_region_a1 id_anchor_a1 id_region_a2 id_anchor_a2 weight level
-    7832 10:10019900..10020058 16755 11:5834473..5834631 2 interchromosomique
-    7832 10:10019900..10020088 16755 11:5834422..5834625 2 interchromosomique
-    --> #id_region_a1   id_region_a2    weight  level
-    --> 7832    16755   4   interchromosomique
+    Use the result of the "interactions" function to add the weights of the
+    same pairs of interactions, e.g.
+    #id_region_1   id_region_2   id_anchor_1   id_anchor_2   level   weight
+    9815_1    16755_2   10:10019900..10020058   11:5834473..5834631 inter   2
+    9815_1    16755_2   10:10019900..10020088   11:5834422..5834625 inter   2
+    --> #id_region_1    id_region_2     weight  level
+    --> 9815_1          16755_2         4       inter
 
-    :param df_filter_2:
-    :return:
+    :param df_filter_2: Result of the "interactions" function
+    :return: df_filter_2 with weights added, when it describes the same pairs
+    of interactions.
     """
     df_filter_2.drop_duplicates(inplace=True)
-    df_filter_2["id"] = df_filter_2["id_region_a1"].astype(str) + "$" + \
-        df_filter_2["id_region_a2"].astype(str)
-    df_filter_2.drop(["id_anchor_a1", "id_anchor_a2", "id_region_a1",
-                      "id_region_a2"], axis="columns", inplace=True)
+    df_filter_2["id"] = df_filter_2["id_region_1"].astype(str) + "$" + \
+        df_filter_2["id_region_2"].astype(str)
+    df_filter_2.drop(["id_anchor_1", "id_anchor_2", "id_region_1",
+                      "id_region_2"], axis="columns", inplace=True)
     df_filter_2["weight"] = df_filter_2["weight"].astype(int)
     df_filter_2 = df_filter_2[["weight", "id", "level"]].groupby(
         ["id", "level"]).sum().reset_index(drop=False)
-    df_filter_2[["id_region_a1", "id_region_a2"]] = df_filter_2.id.str.\
+    df_filter_2[["id_region_1", "id_region_2"]] = df_filter_2.id.str.\
         split("$", expand=True)
     del df_filter_2["id"]
+    df_filter_2 = df_filter_2.reindex(columns=["id_region_1", "id_region_2",
+                                               "weight", "level"])
     return df_filter_2
 
 
 def create_interaction_table(logging_level: str = "DISABLE"):
     """
-    Create the interaction table.
+    Create the interaction tables.
 
     :return: The table of interaction
     """
     logging_def(Config.chia_pet_interaction, __file__, logging_level)
-    logging.debug("Creation of intersection between exons and an anchor")
+    logging.debug("Reading of intersection between genomic regions and an "
+                  "anchor")
     anchor_dic = work_on_intersection()
     logging.debug("Getting anchor couples (PET) and weight")
     df = work_on_pet()
@@ -225,7 +240,7 @@ def create_interaction_table(logging_level: str = "DISABLE"):
     logging.debug("Removing anchor couples (PET) overlapping")
     df = del_overlaps(df)
     logging.debug(df.head())
-    logging.debug("Linking exons interacting with each other")
+    logging.debug("Linking genomic regions interacting with each other")
     df = interactions(df, anchor_dic)
     logging.debug(df.head())
     logging.debug("Sum weight of identical interaction")
@@ -236,4 +251,4 @@ def create_interaction_table(logging_level: str = "DISABLE"):
 
 
 if __name__ == "__main__":
-    print(create_interaction_table("DEBUG").head())
+    create_interaction_table("DEBUG")