<prompt> GNAS mutation is associated with malignancy ofLactotrophsSomatotrophsThyrotrophsCoicotrophs  <response>: GNAS encodes for alpha subunit of stimulatory G-protein , Gsalpha . Oncogenic activation of GNAS constitutively activates Gsalpha leading to Growth hormoneGH adenomas. Ref: Robbins and cotrans 9e Pg 1076 