Nine (associated genes-LGALS3, SLC38A8, SLFN13, CCDC130, HSPB6, CTSZ, MYL9, DOM3Z, CACNA2D4) showed hypermethylation in both LC and ME/CFS, and two (associated genes -IRF2BPL, NMRAL1) were hypomethylated in both conditions. Here, CTSZ is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.