CDKN2A and peritoneal mesothelioma: Similarly, the peritoneal mesothelioma Group 2 (only alterations in CDKN2A/B but not in BAP1) had a higher prevalence of NF2 alterations (prevalence = 48.3%, χ2 = 14.2, P value = 1.0 × 10−3) compared to the entire cohort of peritoneal cases and Group 3 (only alterations in BAP1 but not in CDKN2A/B) had a lower NF2 alteration rate (prevalence = 10.4%, χ2 = 18.0, P value = 2.0 × 10−4).