Glucagon‐like peptide 1 (GLP‐1) counteracts senescence triggered by sera from patients taking capecitabine. Representative pictures (upper part) and percentage (lower part) of SA β‐gal positive EA.hy926 cells after no treatment or incubation with sera obtained from patients with radically resected colorectal cancer either before (Bas) or at the end of six cycles of chemotherapy with capecitabine (S6), in the latter case with or without pretreatment with GLP‐1, E9 (GLP‐1 receptor antagonist), H‐89 (inhibitor of PKA), PD98059 (inhibitor of ERK1/2), LY‐294002 (inhibitor of PI3K) and/or L‐NAME (inhibitor of NOS) as indicated. Magnification 200×, bars 50 μm. * Statistically significant versus CTR, # statistically significant versus S6 and § statistically significant versus GLP‐1 + S6.