C3AR1 and polycystic ovary syndrome: Furthermore, Ccl7 is also known to interact with matrix metalloproteinases (MMPs) (Liu et al., 2018) or complement C3a receptor 1 (C3ar1), a component of the complement known to mediate neutrophil mobilization (Brennan et al., 2019) and lately described as a marker of PCOS progression (He et al., 2020).