CCL8 and viral infectious disease: In addition, the Cytokine-Cytokine receptor interaction KEGG pathway was identified and includes genes such as CXCL8, MPL, CSF1, IL12B, IL5RA, IL1R2, IL10, IL18, TNFSF9, TGFB2, CXCL10, and CCL8. Cytokines are involved in host innate and adaptive immune responses and an increase in the expression of pro-inflammatory cytokines is often observed during viral infections (Saxena and Yeretssian, 2014).