IGF1 and breast cancer: Further, we assessed bioenergetic responses of breast epithelial cells to treatments with host factors, such as, insulin growth factor 1 (IGF1) and tumor necrosis factor alpha (TNFα) because they were associated with breast cancer risk in women (Kaaks et al., 2014; Szlosarek, Charles, & Balkwill, 2006; To, Knower, & Clyne, 2013).