KTN1 and myalgic encephalomeyelitis/chronic fatigue syndrome: Moreover, the 24 h/15 min ratio for KTN1, a protein involved in intracellular transport and cellular organization, showed a strong and significant positive correlation with arthralgia (joint pain) 24 h postexercise (Figure 6C), which suggests that disruptions in cellular transport processes may be linked to joint pain in ME/CFS patients.