After adjusting for other immune cell characteristics within subgroups, there was a significant causal association between IPF and 6 immune cell traits (Fig. 5): CD33 + HLA DR + CD14dim (OR = 0.96, 95% CI 0.93 ~ 0.99, P = 0.033), HLA DR + NK (OR = 0.92, 95% CI 0.85 ~ 0.98, P = 0.017), CD39 + CD8 + T cell %T cell (OR = 0.93, 95% CI 0.88 ~ 0.99, P = 0.024), CD3 on activated & secreting Treg (OR = 0.91, 95% CI 0.84 ~ 0.98, P = 0.026), PDL-1 on CD14- CD16 + monocyte (OR = 0.89, 95% CI 0.84 ~ 0.95, P = 8 × 10–4), CD45 on CD33 + HLA DR + CD14- (OR = 1.08, 95% CI 1.01 ~ 1.15, P = 0.011). This evidence concerns the gene CD8A and idiopathic pulmonary fibrosis.