The results showed that 14 hub genes, including TLR4, MMP9, S100A12, MPO, ELANE, CAMP, S100A8, S100A9, LCN2, CTSG, LTF, IL1R2, SLPI, and PADI4 were significantly up-regulated, while one hub gene IFNG, was significantly down-regulated in ITP patients compared with controls (P < 0.05) (Figure 4), which is consistent with the microarray analysis data. Here, S100A9 is linked to autoimmune thrombocytopenic purpura.