IFNG and systemic lupus erythematosus: Additionally, polymorphisms in non-coding introns of IFNG, which affect its expression, are associated with susceptibility to SLE and nephritis, with a stronger correlation when observed in conjunction with IL18 SNPs (Hirankarn et al., 2009; Miyake et al., 2002; Tangwattanachuleeporn et al., 2007).