LTF was highly up-regulated during infection, peaking at 12 h p.i. HP was less up-regulated, with a 2-fold increase of expression levels at 6 and 12 h p.i., and TF was down-regulated at 6 h p.i. and continued to decrease until 48 h p.i. The gene encoding CD163, a receptor for hemoglobin-haptoglobin complexes, was also significantly up-regulated in response to infection (Table 1). Here, CD163 is linked to infection.