MMP14 and cancer: When cancer cells expressing MT1-MMP, such as HT1080s cells, are trapped in the dense physiologically networked type I collagen scaffolds, such as 2.0–5.0 g/l type I collagen, and broad-spectrum inhibitors of MMPs are supplemented, no MMP-independent invasion is reported (Sabeh et al., 2004; Fisher et al., 2006).