IDH2 and granular cell tumor: Since we identified the same mutation in PDB patients without neoplastic transformation and also considering that H3F3A and IDH2 mutations occur at somatic level, we performed molecular analysis of both genes on tumor tissues derived from 5 GCT/PDB patients, carrying the germline mutation in ZNF687. None of the examined biopsies harboured a mutation neither in these candidate genes nor in the entire coding regions of PDB-related genes (SQSTM1 and ZNF687).