We examined the status of Apc in 20 K14-cre; ApcCKO/+ (16 mixed, 4 C57BL/6 backgrounds) and five WAP-cre;ApcCKO (both WAP-cre;ApcCKO/+ and WAP-cre;ApcCKO/CKO) mammary tumors. Here, APC is linked to breast cancer.