Compared to control lung tissues, 43 differentially expressed MMRGs were identified in lung cancer tissues, including 24 upregulated (ATP4A, ALDH3B2, ATP4B, ALDH3A1, CYP4A22-AS1, ADH1C, GAPDH, PKLR, PPAT, CPT1B, PFKP, PC, PFKP-DT, ALDH1L1, ADH4, GPI, ALDH8A1, ALDH18A1, ATP12A, GAPDHS, NDUFS6, OXCT2, CYC1, and ALDH1L2) and 19 downregulated MMRGs (ADH1B, ACADL, ADH1A, CYP4A26P, PPARG, ALDH1A2, ALDH2, ALDH3B1, CYP4A11, MDH1B, ACSBG1, ACSL4, CYP2U1, CYP4A22, CYP4A27P, ACSL1, PPARGC1A, ACAA2, and PFKFB2). The gene discussed is ALDH1L2; the disease is lung cancer.