Similarly, compared to non-fatigued survivors or healthy controls, fatigued cancer patients had significantly higher levels of pro-inflammatory cytokines, such as C-reactive protein (CRP), IL-1β, IL-6, and TNF-α (102, 103) in the tumor microenvironment (104, 105) or from anti-tumor treatment (radiation therapy or chemotherapy) (106, 107). This evidence concerns the gene IL6 and neoplasm.