Accordingly, mice bearing MCF-7 xenografts treated with pegvisomant, which is the clinical version of the G120R GH antagonist able to completely inhibit both GH and IGF-1 signaling in the mammary gland, displayed a 70–80% decreased of circulating IGF-1 and a 30% decrease in tumor size [61]. The gene discussed is GH1; the disease is neoplasm.