WNT1 and breast neoplasm: The female MMTV-Wnt1/Cav-1+/− mice developed more breast tumors (1.47 tumors vs. 1.14 tumors, P < 0.05) at an earlier age (19.6 weeks vs. 24.5 weeks, P < 0.05) compared with that of parental MMTV-Wnt1 mice (Fig. 4h).