Fig. 2.

The phenotypes and counts of T cell subtypes. a, b Fluorescence-activated cell sorting (FACS) dot plot examples, gated on total CD45⁺ cells (left), the expression of CD4 and/ or CD3 on CD45⁺ cells (middle), and the expression of CD8 and/ or CD3 on CD45⁺ cells (right). Case A indicates one of the moderate patients with COVID-19 (a). Case B, one representative case of severe patients (b). c, d The violin graph showing the counts of CD4⁺ T cells (c) and CD8⁺ T cells (d) in patients with different groups. *** p < 0.001 (Student’s t-test). e ROCs are created by plotting the true positive rate (TPR) against the false positive rate (FPR) at various threshold settings with corresponding AUCs labeled around the curves