CD38 and interstitial lung disease: Additionally, the percentage of CD38+CD8+ T cells were also significantly up-regulated in RP-ILD group as compared with C-ILD group, non-ILD group and HCs, respectively (Figure 3B, RP-ILD vs. C-ILD, P = 0.0018; RP-ILD vs. non-ILD, P = 0.0195; RP-ILD vs. HC, P < 0.0001).