There was a significant positive correlation in all patients with osteoporosis between serum levels of IL-33 and PTH (rho = 0.314; P = 0.026)(Fig. 2), as well as between serum levels of IL-33 and P1NP (rho = 0.373; P = 0.011) (Fig. 3), whereas a significant negative correlation was observed between serum levels of IL-33 and CTX (rho = −0.455; P = 0.002) (Fig. 4). The gene discussed is CYP27A1; the disease is osteoporosis.