In human mammary carcinoma MCF7 cells, GH promoted VEGF-A expression via an autocrine/paracrine effect and subsequent in vitro tube formation in human microvascular endothelial cell line; in vivo, in a xenograft model of human mammary carcinoma, autocrine/paracrine GH increased tumor blood and lymphatic microvessel density (72). This evidence concerns the gene GH1 and neoplasm.