Figure 3.

Stat3 activation is delayed in the absence of Rac1 expression during involution. (a) IHC analysis showing p-Stat3 staining in mammary glands at 10 days of lactation and after 1, 2, 3 and 4 days of involution in MMTVCre⁺Rac1^wt/wt and MMTVCre⁺Rac1^flx/flx mice (scale bar: 100 μm, × 20). (b) Average number of the p-Stat3-positive MECs normalized by the total number of nuclei (%) at the indicated lactation and involution days in MMTVCre⁺Rac1^wt/wt and MMTVCre⁺Rac1^flx/flx mice. Ten random sections were analyzed and quantified from each mouse (n=3). Data were shown as mean±S.E.M. The indicated P-values are calculated by using a two-tailed Student's t-test. NS, not significant, *P≤0.05, **P≤0.01 and ***P≤0.001