The expression levels of five cytokines in APL patients with normal PT or prolonged PT were IL-1β 1.78 (2.74-1.2) vs 2.57 (4.91-1.47) pg/ml, IL-10 4.35 (6.31-3.13) vs 6.98 (31.44-5.07) pg/ml, IL-17A 2.34 (3.87-1.3) vs 3.59 (12.74-2.77) pg/ml, IL-17F 2.95 (4.42-1.72) vs 4.47 (10.49-3.16) pg/ml, TNF-β 2.87 (3.55-1.21) vs 10.12 (15.1-3.57) pg/ml (P< 0.05), suggesting that these cytokines may influence PT elongation. The gene discussed is IL17F; the disease is acute promyelocytic leukemia.