Moreover, an increase in the expression of TNF-α after infection with the GI.1 and GI.2 genotypes (3.1-fold change, and 2.4, for GI.1 and GI.2) at a similar level indicates a similar degree of lung damage (slightly more significant for GI.1), perhaps due to the more extended survival period of the animals. The gene discussed is TNF; the disease is infection.