GH1 and pituitary tumor: The following are the major findings of our study: (a) 48 genes with 59 somatic variants were identified among nine patients using WES; (b) targeted resequencing revealed variants in 26 recurrent genes, including in MAST4, PRIM2, TNN, STARD9, DNAH11, DOCK4, GPR98, BCHE, DARS, CUBN, NGDN, PLXND1, UNC5B, and COL22A1; (c) variants in previously reported genes, such as HMGA2, FGFR4, PTTG1, RB1, GNAS, AIP, and GPR101, were not detected by targeted resequencing; and (d) variants in BCHE, DARS, NGDN, and UNC5B were associated with increased biochemical activity of GH-secreting pituitary tumors.