Estimating pathway activity in a new expression profile to classify disease status has been proved to improve the performance on several disease expression datasets, including tumor necrosis factor (wildtype, mutant), prostate (tumor, normal), acute lymphoblastic leukemia (TEL-AML1, HH), breast cancer (metastatic, non-metastatic), lung cancer (poor prognosis, good prognosis). This evidence concerns the gene TNF and lung carcinoma.