ESR1 and breast cancer: To further test the requirement of Gα13 and RhoA for ERα-induced moesin activation in T47-D breast cancer cells, we performed transient transfections with Gα13 (Gα13 Q226L) or RhoA (RhoA G14V) constitutively active mutated constructs or with Gα13 (Gα13 Q226L/D294N) or RhoA (RhoA T19N) dominant negative constructs (Fig. 6C).