CD4 and AIDS: This is true, especially taking into account that HIV patients in the study of Vollbrecht et al. [29] were at a less advanced clinical stage than those in the study of Qin et al. In other words, most of the enrolled HIV patients (approx. 70%) in the study of Qin et al. were at the C3 clinical stage according to the USA CDC classification system (i.e. patients exhibited acquired immunodeficiency syndrome (AIDS) symptoms; CD4+ T cells greater than 200 per ml).