First of all, consistent with previous literature [24], PTCH1 mutation hot regions in NBCCS-associated KCOTs involved the two large extracellular loops, sterol-sensing domain (SSD), large intracellular loop, and the N terminal region (close to TM1), while PTCH1 mutation hot regions in sporadic KCOTs involved the two large extracellular loops and TM2. Here, PTCH1 is linked to nevoid basal cell carcinoma syndrome.