The potential inflammatory mechanisms between endometriosis and infertility. The figure indicates that various factors may result in infertility in patients with endometriosis. Inflammatory cytokines are secreted by inflammatory cells including TNF-α, IL-1, IL-6, IL-8, NF-κB, MCP-1, leptin, CCR1, MIF, and COX-2. Inflammatory responses depend on locations, populations, and functions of inflammatory cells, which include macrophages, dendritic cells, natural killer cells, T helper cells, and B cells. On the one hand, inflammatory responses alter microenvironment and influence various aspects of fertility; on the other hand, chronic exposure to microenvironments with overproduced inflammatory factors leads to ectopic implant proliferations and angiogenesis, which in turn promote growth and invasion of ectopic endometrium even in the development of cancer.