MSH2 and colorectal carcinoma: To study the effects of CPT-11 on MSH2 expression in CRC cells, DLD-1 cells were kept as control or treated with CPT-11 with 5 μM for 1, 2, 4, 8, and 12 h, or with different doses (0, 0.1, 1, 5, and 10 μM) for 4 h.