When treating serum sTfR as continuous variable, the increase in sTfR (per unit ln-transformed) was significant associated with the prevalence of total cancers in Models I to IV (OR: 1.32, 95% CI: 1.05-1.66, p = 0.0155; 1.53: 1.17-2.01, p = 0.0019; 1.39: 1.01-1.91, p = 0.0444; 1.53: 1.15-2.03, p = 0.0038; respectively). The gene discussed is TFRC; the disease is cancer.