BTN1A1 and chronic obstructive pulmonary disease: There was negative association of Septin-8 and Butyrophilin subfamily 1 member A1 (BTN1A1) with overall COPD risk (Septin-8: OR, 0.68; 95% CI, 0.57–0.79; PFDR = 8.00 × 10−4 BTN1A1: OR, 0.82; 95% CI, 0.75–0.90; PFDR = .010).