In the CD4+ T cells of COVID-19 patients at the two-week convalescent stage, 37 unique pairs of VJ rearrangement of TRA were found, such as TRAV8-4/TRAJ54 and TRAV17/TRAJ54 (Figure 3C), and 23 specific pairs of TRB VDJ patterns were also found in CD4+ T cells (Figure 3D). Here, CD4 is linked to COVID-19.