In a recent study Wang et al. found, Megamonas, Monoglobus, and Prevotella relative abundances were favorably connected with cytokine levels and CD4+ T cell counts; on the other hand, the T helper (Th17)/Treg ratio and the relative abundance of regulatory T cells (Tregs) were correlated negatively with RA disease activity (Wang et al., 2022b). This evidence concerns the gene CD4 and rheumatoid arthritis.