PTEN and breast cancer: Rhein inhibited MCF-7 and MDA-MB-435 BC cell viability and growth by suppressing vascular endothelial growth factor (VEGF)- and endothelial growth factor (EGF)-induced activation of the PTEN/PI3K/AKT/mTOR and MAPK/ERK pathways in BC (Fernand et al., 2011).