Diethylaminobenzaldehyde (DEAB) (ALDH inhibitor), which was used as the control condition to distinguish the ALDH1+ cell population in the human colon cancer cell lines SW403 and SW620 and accurately analyze the altered number and proportion of ALDH1+ cells induced by E2F7, obviously inhibited the proportion of ALDH1+ cells. The gene discussed is ALDH1A1; the disease is colonic neoplasm.