By independent sample t-test analysis, we found that in patients with POCD who had no anemia or had mild anemia, the concentration levels of S-100β at the end of surgery, IL-1β at the end of surgery and 24 h after surgery, and TNF-α at 24 h after surgery were statistically significant compared with those with moderate anemia (p < 0.05) (Figure 5). Here, TNF is linked to anemia (phenotype).