Patients with active disease had significantly higher serum GH compared to inactive disease (6.61 ± 6.40μg/L vs 1.2 ± 1.68μg/L, p=0.001) and IGF-1 concentrations (503.31 ± 253.25ng/mL vs 158.89 ± 54.53ng/mL, p<0.001), larger pituitary tumors both at diagnosis (2.89 ± 1.23cm vs 1.94 ± 0.81cm, p=0.021) and at study entry (1.92 ± 1.32cm vs 0.96 ± 0.49cm, p=0.053) (Figure 1). Here, IGF1 is linked to pituitary tumor.