Although functional studies of GNAS mutations in IMA have not been reported, codon 201 GNAS mutants function as oncogenes in KRAS-driven GEMMs of pancreatic cancer, which expresses some of the same foregut markers as IMA (Patra et al., 2018; Taki et al., 2016). The gene discussed is KRAS; the disease is pancreatic neoplasm.