By utilizing a functional gene knockout technology, CARP-1/CCAR1 was originally identified as a peri-nuclear phospho-protein that was required for apoptosis signaling by a retinoid (CD437) as well as chemotherapeutics Adriamycin (ADR) and Etoposide in the Human Breast Cancer (HBC) cells [3]. Here, CCAR1 is linked to breast cancer.