RAP1A and pachyonychia congenita: Subsequently, combined with gene expression profile from The Cancer Genome Atlas (TCGA) database, we focused on genes involved in the MAPK signaling pathway and identified highly expressed KRAS, GRB2, IGF2BP2, and RAP1A in PC tissues as the most significantly enriched genes, implicating them as potential targets of circular RNA hsa_circ_0006117 (Figure 3(b) and Supplementary figures S3A–S3C).