TNF and Prader-Willi syndrome: These comorbidities were related to chronic inflammation and few studies demonstrated that PWS was associated with increased concentrations of circulating markers of inflammation, such as tumor necrosis factor (TNF) (12), interleukin-6 (IL-6) (13), interleukin-1β (IL-1β) (14), and C-reactive protein (CRP) (13, 15) compared to those with non-syndromic obesity.