Because we did not detect alterations in scar formation in the macrophage MMP-14 mouse mutants (Klose et al., 2013), it is conceivable that collagenolytic activity in scar derives from another enzyme, possibly MMP-13, that is pivotal in this process in liver fibrosis (Fallowfield et al., 2007). The gene discussed is MMP13; the disease is Hepatic fibrosis.