CD44 and cancer: In breast CSCs, a CD44+/CD24− phenotype and high aldehyde dehydrogenase (ALDH) activity are extensively used to determine stemness.29 Hence, to ascertain increased expression of YAP/TAZ specifically in CSCs, CD44+/CD24− and ALDH+ cell populations were isolated from chemo-treated patient breast tumors (Supplementary Fig. S3a), adherent cancer cells and mammospheres (Supplementary Fig. S4a–d).