GH1 and neoplasm: In contrast, female patients with GNAS mutations had significantly smaller maximum tumor diameters (1.55 ± 0.55 vs 2.32 ± 0.85 cm, P < 0.001) and volumes (1.08 (0.51, 1.68) vs 3.58 (1.45, 6.07) cm3, P = 0.003) than those in the non-mutant group, which resulted in a markedly higher GH secretion per unit of tumor volume (20.83 (12.74, 29.93) vs 11.26 (2.87, 18.91) ng/mL cm−3, P = 0.013).