PTCH1 and nevoid basal cell carcinoma syndrome: A principal components analysis (PCA) (Supplementary Figure 1) revealed that although the two treatments clustered separately, i.e., with and without rapamycin, the differences in gene expression due to PTCH1 mutation did not result in a significant clustering and separation of BCNS from normal samples, indicating that the PTCH1 mutation itself, whether truncating or missense, does not alter global gene expression of keratinocytes or fibroblasts enough to provide clear separation between BCNS and normal specimens.