Positive statistically significant correlations were found between serum and peritoneal fluid concentrations of ovarian cancer patients in the case of IL-1α (p<0.001; r=0.57), IL-1β (p<0.05; r=0.44), IL-33 (p<0.001; r=0.65), IL-1Ra (p<0.05; r=0.44), IL-18 (p<0.001; r=0.73) and IL-36α (p<0.001; r=0.68). The gene discussed is IL18; the disease is ovarian cancer.