aromatase inhibitors vs tamoxifen Fu and co workers 17, 18 as well have shown that progestins stimulate breast cancer invasive properties through cytoplasmic signal transduction pathways, involving the G protein GО± 13, the tyrosine kinase c Src, phosphoinositidyl 3 kinase, and RhoA, resulting in the activation of the actin regulatory protein moesin, and remodeling of the actin cytoskeleton
