Previously, we found that C-reactive protein (CRP, a sensitive inflammatory marker), fibrinogen, D-dimer (a coagulopathy marker), and CD8 T cell count (CD8, an immunological marker) were associated with the progression of COVID-19 (An et al., 2021; Jin et al., 2021a; Jin et al., 2021b). The gene discussed is CD8A; the disease is COVID-19.