MRC2 and breast neoplasm: The genetic ablation of uPARAP/Endo180 in mice demonstrated that the uPARAP-driven endocytic route of collagen breakdown is a rate-limiting factor in collagenolysis by fibroblastic cells, chondrocytes, and osteoclasts (Engelholm et al., 2003; Kjoller et al., 2004; Sulek et al., 2007), as well as in collagen turnover in fibrosis (Bundesmann et al., 2012; Lopez-Guisa et al., 2012; Madsen et al., 2012) and in the invasive growth of breast tumors in mice (Curino et al., 2005).