We examined whether ATF1 is required for the stemness marker defined CSC using ALDH, which has been well-established stemness marker in mesenchymal breast cancer cells.47 In agreement with stem-like function, ATF1 depletion results in the ablation of ALDH+ CSC population in MDA-MB-231 cells (Fig. 3g). The gene discussed is ATF1; the disease is breast cancer.