MMP1 and Inguinal hernia: Matrix metalloproteinase 1 (MMP1) expression was increased in scar tissue of the skin from patients with incisional hernia and recurrent inguinal hernias,14but not in patients with primary inguinal hernia.14Similarly, elevated levels of MMP1 have been detected in patients with AAA.15Also, fibroblast cultures from the abdominal skin in direct inguinal hernia patients showed an increased matrix metalloproteinase 2 (MMP2) expression,13MMP2 mRNA levels were increased in incisional hernia samples,14and in serum of AAA patients.15