A study followed 383 patients in the Seroconverter Cohort (SEROCO, a French prospective cohort) study for more than 8 years, and found the relative risk of progression to AIDS for each 1-log10 increase in HIV-1 DNA level was 3.2 [31], while higher CD4+ T cell level [32], higher CD4/CD8 ratio, and a lower level of HIV RNA before treatment predicted a more robust therapeutic effect [14]. Here, CD4 is linked to AIDS.