FAS and pancreatic insulinoma: Mechanistic studies have shown that CHOP knockdown in insulinoma cell lines protected against the downregulation of anti-apoptotic BCL-2-like proteins, Bcl-2 and Mcl-1, while decreasing NF-κB activity and expression of its target genes, including inducible NO synthase (iNOS) and TNF receptor superfamily member 6 (FAS) (180).