BRCA1 and breast carcinoma: To address whether the innate immune response triggered by BRCA inactivation in vitro can be recapitulated in vivo, in the tumor context, we established orthotopic xenograft tumors by injecting BRCA1-compromised MDA-MB-436 mammary breast cancer cells34 into the mammary fat pad of CB17/SCID mice (Fig. 6a, b).