The top 3 sites, based on magnitude difference between ME/CFS GC-Hypersensitive and GC-Typical (ME/CFS and control) subjects, corresponded to GSTM1, MYO3B, and GSTM5, all of which showed >10% increase in methylation. This evidence concerns the gene GSTM5 and myalgic encephalomeyelitis/chronic fatigue syndrome.