CD4 and periodontitis: In addition, when evaluating inactivated CD4+ cells, the expression of IL4 (17.8 ± 3.6 Relative Fluorescence Unit [RFU]), IL13 (19.1 ± 2.8 RFU), and IL2 (18.6 ± 2.8 RFU) were higher than the expression of IFNG (4.9 ± 0.2 RFU) in the periodontitis group; otherwise, the expression of IL4 was greater than the expression of IL2 (10.5 ± 2.6) and IFNG (5.7 ± 1.8) in the cells of the healthy group.