CD4 and medical procedure: As shown in Figure 5, in the regulatory chain of “HLA–DR+CD4+ %T cells–Glutamine degradant levels–Prostatitis,” HLA–DR+CD4+ %T cells positively influence the metabolic pathway of glutamine (beta = 0.045 > 0), while this pathway negatively regulates the risk of prostatitis (beta = −0.267 < 0).