Candidates for screening include all patients with Peutz Jeghers syndrome, carriers of a germline CDKN2A mutation, carriers of a germline BRCA2, BRCA1, PALB2, ATM, MLH1, MSH2, or MSH6 gene mutation with at least one affected first-degree blood relative. The gene discussed is CDKN2A; the disease is Peutz-Jeghers syndrome.