In this study, we have demonstrated the differential expression of imatinib targets (c-kit, PDGFR-α/β, and VEGF) in different pituitary adenomas subtypes and we have shown that imatinib decreases GH secretion in cultured somatotropinoma cells and GH3 cell line acting through PDGFR-β pathway. The gene discussed is VEGFA; the disease is growth hormone-producing pituitary gland neoplasm.