In a side-by-side comparison of chickens and mallard ducks infected with HPAI A/Vietnam/1203/2004 (H5N1), there was a 2-fold decrease of IFITM3 mRNA in chicken ileum, and no change in chicken lungs, whereas in ducks IFITM3 was upregulated 12-fold in lungs and 10-fold in ilea on the first day post-infection [40]. The gene discussed is IFITM3; the disease is infection.