CXCL8 and bacterial infectious disease: Cyprinid fish such as zebrafish and carp encode two distinct Cxcl8 genes (11, 12) corresponding to two Cxcl8 homologs that have been designated as Cxcl8_L1 and Cxcl8_L2. The expression of both fish Cxcl8_L1 and Cxcl8_L2 genes is upregulated in response to bacterial infection (13) and wound-associated inflammation (12).