In a study to determine the roleof these cell populations in the pathogenesis of chronic ACL by employing PBMCs, it wasobserved that CD4+CD25+ cells from individuals with asymptomatic infection have a highercapacity to suppress CD4 effector T cell IFN-g secretion than those from patients withchronic ACL (Rodríguez-Pinto et al. 2012). This evidence concerns the gene CD4 and infection.