CI-994 is a histone deacetylase (HDAC) inhibitor that induces histone hyperacetylation. CI-994 inhibited HDAC-1 and HDAC-2 but not GCN5. CI-994 is also a novel antitumor agent, exhibiting activity against pancreatic, colon and mammary tumors. CI-994 inhibited the growth of two non-small cell lung cancer cell lines, A-549 (adenocarcinoma) and LX-1 (squamous cell carcinoma), with an IC50 of 80 µM._x000D_