The most commonly viewed members of the metalloproteinase group in PC are MMP-2, -7, -9 and membrane-type-1 matrix metalloproteinases (MT1-MMP) while, in more detail, MMP-2, MMP-7 and MMP-9 have been shown to stimulate PC angiogenesis [55]. The gene discussed is MMP14; the disease is pachyonychia congenita.