WWP1 and breast cancer: Consistent with previous studies [24], over-expression of WWP1 caused enhanced cell proliferation in LATS1-positive MCF10A mammary epithelial cells (Fig.4C and Fig. 6A), whereas knockdown of WWP1 by short-hairpin (sh) RNA (shWWP1-1 and shWWP1-2) in MCF7 breast cancer cells expressing functional wild-type LATS1 [16] significantly inhibited cell proliferation (Fig. 6B and 6C).