Because the majority of primary BCC mutations are in Patched 1(PTCH1) and the majority of resistant mutations are in Smoothened (SMO) [9,10], we performed targeted exon sequencing of both PTCH1 and SMO on pre-treatment formalin-fixed paraffin-embedded (FFPE) biopsy sections to identify variants of interest in pre-vismodegib opBCC tumors. This evidence concerns the gene SMO and skin basal cell carcinoma.