Nevi most often harbored canonical MAPK-pathway mutations in BRAF and NRAS, as well as in GRIN2A, while melanomas, along with BRAF and NRAS, frequently carried additional driver alterations in ARID1A, ARID2, CDKN2A, and PTEN (Table 1, Figure 2). The gene discussed is CDKN2A; the disease is melanoma.