Compared to patients who did not have a post-operative infection, patients who developed an infection had a higher monocyte count (p = 0.0487), higher CD4+ lymphocyte IL-7R (p < 0.0001) and CD8+ lymphocyte IL-2R (p = 0.0114) expression, and lower monocyte CCR2 (p = 0.0079) and PD-L1 (p = 0.0028) expression before and after surgery. The gene discussed is CCR2; the disease is infection.