IL17A and myelodysplastic syndrome: We further tried to explore the pathway through which Th17 cells exerted their effects and found that comparing with H-MDS group, the expression of Per, GB in CTL of patients with L-MDS was notably higher (Figures 6(e)-6(f)); correlation analysis showed that the expression of Per and GB in CTL negatively correlated with BM blast% (Figures 6(g)-6(h)) and positively correlated with levels of BM IL-17 (Figures 6(i)-6(j)).