Abiotic IL10−/− mice treated with artificial vitamin D suffered less diarrhoea and had lower levels of intestinal IL-6, IFN-γ and CCL2 during campylobacteriosis than mice that did not receive vitamin D [55], therefore the contribution of vitamin D and the vitamin D receptor to C. jejuni susceptibility in line N chickens warrants further study. This evidence concerns the gene CCL2 and campylobacteriosis.