CD163 and neoplasm: There was a weak negative correlation between serum IL-6 and tumor-infiltrating CD8-positive cells (ρ = −0.267), a weak positive correlation between serum IL-6 and the number of CD163-positive cells (ρ = 0.295), and a significant negative correlation between the CD8/CD163-positive cell ratio (ρ = −0.42, p = 0.00071) (Fig. 3c and d).