Other proinflammatory cytokines (TNFα, IL1β, IL8, and MCP1 with different roles in the host's immune response to infection29,30) were detected in practically all samples from mastitis cases and at higher levels (eightfold, sevenfold, fourfold and twofold increase, respectively) than those from healthy women, in agreement with previous reports31,32. Here, CXCL8 is linked to mastitis.