Our recent pre-clinical studies have revealed an unexpected immune modulator in a murine TNBC-like model, with the demonstration that mammary tumors in mice null for insulin-like growth factor binding protein-3 (IGFBP-3) grow 50% smaller than those in wild-type mice and show increased accumulation of CD8+ lymphocytes (8). The gene discussed is IGFBP3; the disease is breast cancer.