diff --git a/session_4/session_4.Rmd b/session_4/session_4.Rmd
index fb366bcb6b67c9cb4f2d27c631c7ae242750ee88..34f337be122055d09860a900b2fc331d05e41caf 100644
--- a/session_4/session_4.Rmd
+++ b/session_4/session_4.Rmd
@@ -479,7 +479,7 @@ Open the csv file using the `read_csv2()` function. The file is located at "XXX"
 <details><summary>Solution</summary>
   <p>
 ```{r read_csv1}
-expr_DM1 <- read_csv2("XXX/Expression_matrice_pivot_longer_DEGs_GSE86356.csv")
+expr_DM1 <- read_csv2("http://perso.ens-lyon.fr/laurent.modolo/R/session_4/Expression_matrice_pivot_longer_DEGs_GSE86356.csv")
 
 expr_DM1
 ```