CCL2 and male infertility: EAO is a well-established mouse model of autoimmune-based male infertility featuring marked testicular deposition of ECM proteins (including collagens and fibronectin), increased numbers of TMs, and elevated levels of inflammatory mediators such as TNF, CCL2, and activin A. These pathological alterations combine to cause tissue destruction, inhibition of spermatogenesis, and subsequent infertility [8, 13, 21, 24].