GNAS and neoplasm: Molecular analysis of pancreatic cystic fluid has been reported to be possibly useful in identifying mucinous cysts and detecting neoplasia, with a recent systematic review and meta-analysis by McCarty et al., including six studies (785 lesions) reporting a sensitivity of 75% and specificity of 99% in identifying IPMNs and mucinous cystadenomas by using combined KRAS and GNAS testing.