TNF and mastitis: In addition to TNFa and IL-1b, CASP1 and NFKB1 were found to be up-regulated in our study (Additional file 1: Table S1) suggesting that TREM1 signaling may likely provide the link between TLR2- and NLR-mediated signal transduction in cytokine-induced inflammation during the initiation of host defense such as in mastitis.