In cultured colon cancer cells, we showed that expression of caspase-3 and −9 significantly decreased after the treatment with PKC inhibitors except Rottlerin treatment in DLD-1 cells and Bis-I treatment compared to normal colon cells CCD18Co, but we observed significant increases in the expression levels of autophagy genes Atg5 and LC3A/B in colon cancer cells except for LC3A/B in SW620. Here, ATG5 is linked to malignant colon neoplasm.