The numbers of CD3+ (p = 0.014), CD3+CD4+ (p = 0.006) and CD3+CD8+ (p = 0.001) cells in the peripheral blood of the HFMD group were significantly lower than those in the control group, whereas the number of CD3−CD19+ cells (p = 0.007) in the peripheral blood of the HFMD group was significantly higher than that in the control group (Table 1). This evidence concerns the gene CD4 and hand, foot and mouth disease.