There are two possible reasons for the predominant expression of the Slit2-WT isoform in the lung cancer specimens: (1) people with the Slit2-WT isoform are at a higher risk of lung cancer, since Slit2-WT lacks the ability to inhibit cell proliferation, and (2) the expression ratio of Slit2-WT/Slit2-ΔE15 changes in response to the development of lung cancer. The gene discussed is SLIT2; the disease is lung carcinoma.