CD4 and HIV infectious disease: We found that both mitochondrial (Figure 1C) and cytosolic extracts (Figure S1D) from CD4 T cells derived from these patients failed to completely relax the supercoiled plasmid DNA compared with CD4 T cells from HS, indicating a reduced level of Top1 enzymatic activity in the mitochondria and cytosol of CD4 T cells from patients with HCV or HIV infection.