SIX1 and pineal parenchymal cell neoplasm: Of these, three were somatically acquired and included a disease-defining mutation of KBTBD4 (p.R313_M314insPRR) in a pineal parenchymal tumor of intermediate differentiation29,30, a SETBP1 (p.D868N) mutation in a germ cell tumor, and a SIX1 mutation (p.Q177R) in a Wilms tumor31.