IL6 and neoplasm: Furthermore, IL-6 dynamics between weeks 0 and 2 were found to differ depending on patients’ early PET-based hypoxia response: While patients with absent tumor hypoxia response within the first 2 weeks of treatment exhibited a considerable increase of IL-6 plasma levels (Δ16.0 ng/mL), patients with early hypoxia response (Δ[18F]FMISO T/M-ratioweek 0-2 <0) were found to have rather stable IL-6 levels (Δ2.1 pg/mL, p=0.126).