Numerous studies have reported a significant correlation between increased tumor-related fatigue and depression with elevated expression of pro-inflammatory cytokines IL-1β and IL-6 mRNA in the cortex and hippocampus (Pyter et al., 2009; Yang et al., 2014; Norden et al., 2015; Santos et al., 2019). The gene discussed is IL6; the disease is major depressive disorder.