PTCH1 and skin basal cell carcinoma: Consistently, BCC markers (PTCH1, GLI1, GLI2, HHIP, and MYCN) as well as Hedgehog signaling pathway and BCC KEGG signatures were enriched in cluster C0 when compared to clusters C1, C2 and C3 (and T cells) (Fig. 1h and Supplementary Fig. 3a–b).