TLR4 and pulmonary emphysema: The TLR4 low expresser group included a higher number of severe-stage emphysema cases; the proportions of severe compared with mild emphysema in the high, intermediate, and low expressers were 43.8% (7/16), 72.0% (18/25), and 83.4% (10/12) (P = 0.007, Figure3B).