F2R and myalgic encephalomeyelitis/chronic fatigue syndrome: In contrast, the severity of cognitive symptoms correlated positively with F2R/PAR-1-, CXCR3-, and STAB1-Ab, and immune symptoms correlated with EDNRB-, BDKRB1-, and CHRM5-Ab in PCS/ME/CFS, while the severity of muscle pain and headache showed no significant correlations.