HDAC8 and cancer: HDAC8 is a unique Class I HDAC that recognizes both histone and nonhistone substrates.[29] Overexpression of HDAC8 has been observed in a variety of cancers (colon cancer, lung cancer, breast cancer, pancreatic cancer, optic neuroblastoma, etc.), and HDAC8 has become an important drug target for the treatment of a variety of diseases.[29] However, whether HDAC8 and specific HDAC8 inhibitors are involved in the regulation of ccRCC sensitivity to sunitinib has not been reported.