HDAC9 and neoplasm: However, the pan-HDAC inhibitor Vorinostat inhibited TAM infiltration in estrogen receptor negative PyMT mammary tumors, thereby delaying tumor growth (39, 40), and inhibited tobacco smoke-related increase of F4/80+ Arg-1+ M2-like macrophages in a murine KRAS-driven pancreatic cancer model (39, 40).