In particular, tamoxifen could serve as an agonist of ERα36 and enhances the stemness and metastasis of breast cancer cells via enhancing aldehyde dehydrogenase 1A1 and cause breast cancer cells to proliferate, invade, and metastasize (Wang Q. et al., 2018; Pagano et al., 2020). The gene discussed is ALDH1A1; the disease is breast carcinoma.