GNAS-activating mutations have been identified across many cancer types, such as pancreatic adenocarcinoma, squamous cell carcinoma of the head and neck, breast neoplasm, gastric adenocarcinoma, adrenal cortex carcinoma, and sex cord-stromal tumor, as well as in fibrous dysplasia and LSMFT. The gene discussed is GNAS; the disease is adrenal cortex carcinoma.