Furthermore, the effector function of TIGIT+CD226+ CD4 T cells was correlated with the disease status: the HLA-DR expression on TIGIT+CD226+ CD4 T cells in DM patients with ILD (n = 5) was significantly higher than that in DM patients without ILD (n = 5) (Fig. 3b, 16.07 ± 3.990% vs 7.03 ± 1.976%, p = 0.0019). Here, CD4 is linked to interstitial lung disease.