SGCG and cancer: Consequently, increased levels of tissue and cancer-specific ECM turnover products (ECM neo-peptides) are released into the circulation, including specific fragments of MMP-mediated degradation of type I, III and IV collagen (C1M, C3M, C4M), and type III and VI collagen formation (pro-peptides PRO-C3 and PRO-C6) [23–27].