The top 10 proteins (MIG6, GAPDH, NDRG1_pT346, BRD4, CD26, TFRC, INPP4B, GSK3ALPHABETA, IGFBP2, and DUSP4) were screened by applying the WBFS algorithm, and they can be regarded as the candidate biomarkers that are most closely associated with the classification of lung cancer subtypes. The gene discussed is IGFBP2; the disease is lung cancer.