CLPP and cancer: Another aspect of MMP11 role in mediating cancer progression is the altered mitochondrial unfolded protein response (UPRmt) observed in tumors from PyMTTg; MMP11Tg mice as demonstrated by the decreased expression of important proteins of the UPRmt such as the chaperone proteins HSP10 and HSP60 or the mitochondrial protease CLPP, which role is to eliminate misfolded or unfolded proteins in the mitochondrial matrix.