The concentration of IFN-γ in the serum was lower in the histiocytic sarcoma group (30.82 ± 16.35 pg/mL) than in the other tumor group (73.41 ± 61.91 pg/mL); however there were no significant differences between the three groups (control group: 30.63 ± 25.65 pg/mL). The gene discussed is IFNG; the disease is histiocytic sarcoma.