BSG and COVID-19: However, the more recently identified SARS‐CoV‐2 docking receptor basigin (Wang et al., 2020) (BSG or CD147) was expressed in 95% of secretory cells in aged patients with critical COVID‐19 (Figure 4d and Table S6); furthermore, BSG and CD147 showed elevated expression in Treg (regulatory T cell) and CD8 T cells (Figure 4d) as well.