Among the 22 genes with CpG sites that distinguished melanomas from nevi, half possess immune-related functions, with several, including ITK and LAT (Andreotti et al., 2010), CD2 (Sewell et al., 1986), TNFSF8 (Kennedy et al., 2006), IFNG (Lee et al., 2006b), and IL2 (Kallies, 2008) operating in T-cell regulatory pathways. The gene discussed is IFNG; the disease is melanoma.