To study whether HO-1 overexpression induces stemness in our model of CRC in vitro through ET-1 produced by ECE-1, we analyzed the percentage of ALDH1+ cells after HO-1 overexpression in the presence of bosentan, an antagonist of both ETRA and ETRB receptors. This evidence concerns the gene ALDH1A1 and colorectal carcinoma.