This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Matrix metalloproteinases is ? 
Select and explain. 
A. Cathepsin, B. Zn metalloproteinases, C. Cu metalloproteinases, D. Cd metalloproteinases
A: Cathepsin
Answer: A: Cathepsin 
Explanation: Ans. is b i.e., Zn metalloproteinases The outcome of the repair process of tissues is influenced by a balance between synthesis and degradation of ECM proteins. After its deposition, the connective tissue in the scar continues to be modified and remodeled. The degradation of collagens and other ECM components is accomplished by a family of matrix metalloproteinases (MMPs), so called because they are dependent on metal ions (e.g., zinc) for their activity. MMPs include interstitial collagenases, which cleave fibrillar collagen (MMP-1, -2 and -3); gelatinases (MMP-2 and 9), which degrade amorphous collagen and fibronectin; and stromelysins (MMP-3, -10, and ,11), which degrade a variety of ECM constituents, including proteo- glycans, laminin, fibronectin, and amorphous collagen.