Increased methylation was observed at GpG sites of (a) GSTM1, (b) MYO3B, and (c) GSTM5 in the ME/CFS GC-Hypersensitive (black) compared to ME/CFS GC-Typical (grey) and Controls (white). The gene discussed is GSTM5; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.