PTEN and Familial prostate cancer: Although preclinical models have shown that inhibition of PI3Kβ or AKT enhances docetaxel cytotoxicity in PTEN-loss prostate cancer (Davies et al., 2012; Hancox et al., 2015), to the best of our knowledge, no studies have evaluated the effect of the combined inhibition of the PI3K/AKT and MEK/ERK pathways in docetaxel-resistant mCRPC patients.