To investigate whether JNK activation is a key determinant for the up-regulation of LC3 during 5-FU-induced autophagy in p53-deficient and mutant p53-expressing colon cancer cells, the abundance of MAPKs and phosphorylated forms of these proteins were assessed by western blotting using specific antibodies in HCT116 p53+/+, HCT116 p53−/−, RKO and HT-29 cells treated with various concentrations of 5-FU for 24 h. This evidence concerns the gene MAPK8 and malignant colon neoplasm.