As shown in Figure 6(c), the risk score was positively correlated with most immune cells, such as activated CD4 T cells, natural killer T cells, type 1 and 2T helper cells, regulatory T cells, and so on, which implied the ability of the risk score to reflect immune cell infiltration and complex interplay between immune cells in the synovium of RA patients. The gene discussed is CD4; the disease is rheumatoid arthritis.