IL7R and chronic obstructive pulmonary disease: Furthermore, predictor screening and effect ranking for predictive factor optimization showed that the highest ranked contributors to or determinants of emphysema (COPD-E) severity were BMI (contribution: 2.31, portion: 0.21, rank: 1), lnc-IL7R (contribution: 2.04, portion: 0.19, rank: 2), PM2.5 (contribution: 1.33, portion: 0.12, rank: 3), PM10 (contribution: 0.98, portion: 0.09, rank: 4), and SO2 (contribution: 0.81, portion: 0.07, rank: 5) (Figure 5A).