PTX3 and infection: Previous studies had measured gene expression responses in milk SC and in blood immune cells in response to infection with Staphylococcus aureus in cow (Tao and Mallard, 2007) and in goat (Cremonesi et al., 2012) and showed that despite some specific similarities such as the induction of the gene pentatrexin 3 (PTX3) involved in the regulation of innate resistance to pathogens, there were not many other coincidences in the gene response in both type of cells.