To determine the relationship between Top1 levels and CD4 T cell numbers in patients with HIV infection, we measured Top1nc protein levels in mitochondrial and cytosolic extracts from antiretroviral therapy (ART)-treated HIV patients with CD4 T cell counts > 500 cells/μL (defined as HIV immune responders/HIV-IRs) and CD4 T cell counts < 500 cells/μL (defined as HIV immune non-responders/HIV-INRs) (Zhao et al., 2021) and compared them with those from HS. Here, TOP1 is linked to HIV infectious disease.