Based on our results, we propose to retest with GST all CO-GHD patients with organic GHD (brain tumors, congenital anomalies, irradiation to the hypothalamic/pituitary region) with 0, 1, or 2 pituitary hormone defects with IGF-1≥ −2 SDS, and patients with idiopathic GHD with IGF-1 < 0 SDS (Fig. 6). The gene discussed is IGF1; the disease is brain neoplasm.