IGFBP3 and breast cancer: A number of factors with potent growth-inhibitory and apoptosis-inducing effects have been shown to induce the expression and secretion of IGFBP-3 in breast cancer cell lines, including 1, 25-dihydroxyvitamin D3 (1, 25-D3), the active metabolite of vitamin D3 which has been shown to inhibit breast cancer cell growth [7].