CD4 and COVID-19: When comparing biochemical indexes of COVID-19 between moderate cases with and without progression, we found that there were significant differences in lymphocytes, NLR, CRP, AST, TBIL, DBIL, Cr, urea, glucose, sodium, PT, CD3+ T cells, CD4+ T cells, CD8+ T cells, CD19+ T cells, CD16+/ CD56+ NK cells between patients with and without progression (all p < 0.05); detailed information are listed in Table 2.