COL4A1 and aneurysm: so the COL4A1 was tightly associated with the cell proliferation, it was reported that COL4A1 knockdown led to reduced cell viability and cell cycle arrest [15], and clinical performance associated with mutations of COL4A1 include perinatal cerebral hemorrhage and porencephaly [16], hereditary angiopathy, nephropathy, aneurysms, and muscle cramps (HANAC) [17], ocular dysgenesis, myopathy and Walker-Warburg syndrome [18].