HSP90B2P and myalgic encephalomeyelitis/chronic fatigue syndrome: Importantly, several research teams have reported that levels of oxidative stress in the muscles of exercising CFS patients are higher than in age- and sex-matched controls and that protective heat shock protein (HSP) responses are impaired (Jammes et al. 2005, 2009, 2011, 2012; Thambirajah et al. 2008).