As shown in Figure 1, when the regularization parameter λ reached its minimum value (λ_min = 0.00279), 11 key variables were selected: MLR, NLR, pulmonary heart disease (PHD), PLR, CRP, ELR, age, NT-proBNP, BLR, RDW, and SII. The gene discussed is CRP; the disease is cor pulmonale.