Fifth, PIN1 knockdown or pharmacological inhibition sensitizes cancer cells of different origins to chemo- and target therapy, such as breast cancers to 5-fluorouracil, Taxol (151), and rapamycin (171), hepatocellular carcinoma to sorafenib (172), colon cancer to Taxol (72) and acute myeloid leukemia to retinoic acid (173). This evidence concerns the gene PIN1 and breast cancer.