However, upon infection with SE, we found 11 of the TLR reference genes that were significantly up-regulated in heterophils from line A when compared to line B (MD-2, TIRAP, IRAK4, TRAF3, TAK1, IKKε, IKKα, NF-κB2, PI-3K, p38, and IRF7). The gene discussed is IRAK4; the disease is infection.