SMO and basal cell carcinoma: The mechanisms of SMO regulation bring a lot interest in the SMO research field because abnormal SMO activation often results in basal cell carcinoma and medulloblastoma, and SMO has been an attractive therapeutic target [19,20], exemplified by the U.S. FDA-approved drugs, such as vismodegib, sonidegib, and glasdegib, for the treatment of cancers known to be driven by SMO activation [21,22,23,24].