GNAS and neoplasm: We found 22 tumor-related gene mutations (APC, KRAS, SMAD4, ERBB4, TCF7L2, AMER1, TP53, GNAS, ARID2, RET, MTOR, NRAS, ACVR1B, GNAQ, ATM, PIK3CA, ERBB2, TRRAP, MAP2K4, MAP3K4, CNOT1 and EP300) from 12 HGCAs that harbored 2-7 of these mutations per case.