Conflicting results show MutS homolog 2 (MSH2) loss in 5% of NEPC [142] and approximately 30% incidence of BRCA2 alterations in AVPC-c [93] (Table 3), in line with the association of BRCA2 mutations with low PSA levels in metastatic PC [143]. The gene discussed is BRCA2; the disease is pachyonychia congenita.