HSP90B2P and myalgic encephalomeyelitis/chronic fatigue syndrome: This is pertinent given that HSP production appears to be deficient in CFS patients, and the HSPs produced appear to be dysfunctional, which could potentially provide another mechanism underpinning a prolonged and/or exaggerated immune response to pathogen invasion and other sources of inflammation such as stress, medical comorbidity and lifestyle factors in such patients (Elfaitouri et al. 2013; Jammes et al. 2005, 2009, 2011, 2012).