AKR1A1 and ovarian neoplasm: PE5 also down-regulates the expression of two enzymes directly involved in the MDR phenotype: i) aldo-keto reductase family 1 member A1 (AKR1A1) that metabolizes anthracyclines into inactive compounds [116] and has been associated with acquired resistance to irradiation [117]; ii) prosaposin (PSAP), present among the 20 most PE5 down-regulated genes (Table S1 Supplementary Data), found overexpressed in ovarian tumors after chemotherapy [118] and involved in estrogen chemotherapy resistance [119].