In the case of the cytokine–cytokine-receptor interaction pathway, other genes, such as CD40, IL1RN, CXCR1, TNFRSF6B, and CCL19, were found to be involved in mastitis defense or immune response, as all these genes were upregulated in the mastitic cows based on their FC values. The gene discussed is IL1RN; the disease is mastitis.