TNF and myeloid sarcoma: While the GG genotype of rs222747 is linked to enhanced glutamate transmission in the brain (Mori et al., 2012), MS patients carrying this genotype are known to display exacerbated symptoms (Buttari et al., 2017), even though the same SNP seems to reduce TNFα cytokine expression in the CSF which has been proposed to alleviate the disease (Taoufik et al., 2011).