GNA11 (guanine nucleotide-binding protein subunit alpha-11) is a GTPase activated upon ligand binding of a G-protein coupled receptor. Hotspot mutations impair GTPase activity, resulting in constitutive pathway activation and are common in uveal melanoma. Simple variants in GNA11 are seen in about 1% of all tumors, 2% of skin tumors, and in 37% of eye tumors, where it is diagnostic for uveal melanoma.