The infection of SARS-CoV-2 can lead to lymphocytopenia and imbalance of lymphocyte subsets, such as decreased CD4+ T cells, CD8+ T cells, B cells, and NK cells (Guan et al., 2020; Wang et al., 2020b; Zhang et al., 2020; Xu et al., 2020). Here, CD4 is linked to infection.