While there are no clinical studies suggesting hookworm infection is a risk factor for asthma (28, 29), a mouse model of hookworm (using Nippostrongylus brasiliensis) found larval migration through the host lungs and mucosal damage increased expression of Trefil factor 2 (TFF2), a central effector molecule in asthma. The gene discussed is TFF2; the disease is asthma.