CD4 and interstitial lung disease: Compared with the control group, the percentage VSTs of CD4+ or CD8+ T cells was significantly suppressed in patients with ILD compared with the control individuals at 7 and 14 days PSO, and suppressed VST profiling was observed in patients with ILD on day 7 (CD4+ VSTs: ILD 0.012 vs. control 0.082, p = 0.06; CD8+ VSTs: ILD 0.003 vs. control 0.012, p = 0.17), persisting until day 14 (CD4+ VSTs: ILD 0.018 vs. control 0.082, p = 0.005; CD8+ VSTs: ILD 0.0008 vs. control 0.047, p = 0.004) (Figure 3A,B).