De-5-fluoro 4-Fluorochidamide-d4 is the labeled analogue of De-5-fluoro 4-Fluorochidamide (D289910), an analogue of Chidamide (CAS 743420-02-0), which is a hitsone deacetylase inhibitor (HDACI) that enhances gemcitabine (G305000) cytotoxicity in pancreatic cancer cells.