VDR and neoplasm: While tumor size did not differ for females between ApcPirc/+VDR+/+ (7.2±3.1 mm2) and ApcPirc/+VDR−/− (10.1±8.7 mm2, P=0.7), tumors from ApcPirc/+VDR−/− male rats (9.5±6.5 mm2) were substantially smaller than from their ApcPirc/+VDR+/+ counterparts (15.5±12.7 mm2, P=0.02, Fig. 2C).