GLI1 and skin basal cell carcinoma: Gli1(S941E) knock-in significantly increases the overall survival rate in Smo-M2-derived MBSHH and p-Ser937-GLI1 positively correlates to the overall survival rate of children with MBSHH, both suggest the determinant role of phosphorylation on Ser937/SerS941 of GLI1 in the incidence and severity of MBSHH and BCC.