CD28 and Ito hypomelanosis: The CD8+ and CD28+CD8+ T-cell counts had greater discriminatory ability than the other immune parameters to predict 28-day mortality in CIIC patients with IPA, with area under the curve (AUC) values shown in Figure 2: CD8+ T-cell counts for D1 (AUC 0.82, 95% CI 0.71 to 0.92; P < 0.001), D3 (AUC 0.94, 95% CI 0.87 to 0.99; P < 0.001) and D10 (AUC 0.94, 95% CI 0.85 to 0.99; P < 0.001); and CD28+CD8+ T-cell counts for D1 (AUC 0.84, 95% CI 0.75 to 0.94; P < 0.001), D3 (AUC 0.92, 95% CI 0.85 to 0.99; P < 0.001) and D10 (AUC 0.90, 95% CI 0.79 to 0.99; P < 0.001).