Next, to test the phenotypic response to altering ALDH1A3 and TFAP2B, we found that ALDH1A3 KO led to decreased colony formation while ALDH1A3 OE increased colony formation in both A375 and C089 (Figures 2F–2H), consistent with the pan-cancer effect of ALDH activity in cancer stem-like states.42 This evidence concerns the gene ALDH1A3 and cancer.