MMP9 and Alzheimer disease: This phenomenon may be explained by severalreasons as follows: AA/AD in humans is usually caused by decades of damage tovessels, but animal models were induced in ˂1 month; application of CaCl2induces AA and results in the absence of MMP2 and MMP9, but they are abundant inhuman AA and have a dramatic pro-angiogenic effect; and mural thrombosis iscommon in human AA/AD, and the thrombus-covered wall is hypoxic, particularly inthe inner thirds of the media, but all of the above-accepted models are withoutan obvious mural thrombus [31].