IL6 and endometriosis: In women affected by endometriosis, the peritoneal fluid contains: elevated levels of immune cells which demonstrate increased susceptibility to apoptosis, elevated concentrations of pro-inflammatory mediators/cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6, dysfunctional macrophages and NK cells, and highly accumulated regulatory T suppressor cells which promote inflammation as well as stand behind the initiation and progression of endometriosis-associated ovarian cancer [6–8].