A recent nationwide HIV molecular epidemiologic survey by China CDC discovered that people infected with CRF01_AE cluster 5 had significantly higher CD4 count than those infected with CRF01_AE cluster 4 [17]; meanwhile, our unpublished data based on general population found that CRF55_01B-infected MSM had even higher CD4 count than those infected with CRF01_AE cluster 5, which may be attributed to the slower loss of CD4 count caused by infection with CRF55_01B than with CRF01_AE. The gene discussed is CD4; the disease is infection.