HDAC9 and colonic neoplasm: However, in colon cancer cells, Romain et al. observed that non-specific HDAC inhibition by vorinostat, valproic acid, butyrate increased CXCL12 expression, which was otherwise decreased in both MSI and MSS colon cancer tumors, warranting more studies on the roles of specific HDACs on CXCL12 expression [106].