GCG and cancer: MAF expression has also been associated with multiple sclerosis (Zhang et al., 2017), a range of cancers including renal cancer (Ponten et al., 2008), glucagon expression and biosynthesis (Planque et al., 2001; Kataoka et al., 2004; Gosmain et al., 2007) and autoimmune diabetes (Pauza et al., 2001).