CD274 and chronic obstructive pulmonary disease: After expanding by n numbers, we confirmed that the ratio of PD-L1+ cDC1 was lower in the patients with COPD (n = 54) than in the normal subjects (n = 29) (13.7 ± 13.7% vs. 32.7 ± 33.1%, respectively; p = 0.03, Figure 1A).