Insulin-like Growth Factors (IGFs) are a determining factor in breast cancer development since high circulating concentrations of IGF-I are associated, in previous epidemiological studies, with an increased risk of breast cancer. The actions of IGF-I, which plays an important survival role for several cell types and protect cells from apoptosis, is modulated by a family of IG; proteins (IGFBPs) IGFBP-5 has been proposed to induce cell death of epithelial and mesenchymal cells, but, failed to enhance mammary epithelial cell attachment. This research initially examined the effects of growth factors on mammary cell survival and attachment. IGF-I was consistently the best survival and proliferative factor tested for epithelial and mesenchymal cells, but, failed to enhance mammary epithelilial cell attachment. This research initially examined the effects of growth factors on mammary cell survival and attachment. IGF-I was consistently the best survival and proliferative factor tested for epithelial and mesenchymal cells, but, failed to mammary epithelial cell altachment.