APOA2 and non-small cell lung carcinoma: Modeling with small-molecule metabolites and DEPs in NSCLC and BPD groups (ApoA1, ApoA2, ApoB, ApoC3, Lp(a), C3, FN, Fg), ended up with a 6-variable model (Cit, GDCA, TCDCA, ApoA2, C3, Lp(a)).