IL6 and anemia: It has been shown that among other risk factors lymphopenia, specifically reduced numbers of CD4+ and CD8+ T-lymphocytes, high numbers of neutrophils, dysfunctional monocytes, higher circulating concentrations of immune biomarkers such as interleukin 6 (IL-6), IFN-gamma or neopterin as well as higher ferritin levels or presence of anemia at diagnosis were associated with an adverse outcome (Bellmann-Weiler et al., 2020, 2021; Manson et al., 2020; Schulte-Schrepping et al., 2020; Zhang et al., 2020b; Lanser et al., 2021b).