Our data demonstrate that 1 and 2 reduce the putative CSC population in both A375 and SSM2c melanoma cells already at 250 nM, paralleling results obtained with genetic silencing of SMO, GLI1 or treatment with GANT61 (ref. 40) These data suggest that both compounds have good selectivity against melanoma CSCs, making them promising candidates for further pre-clinical and clinical studies in melanoma and other types of cancer. The gene discussed is SMO; the disease is melanoma.