Updated project metadata. CARASIL (cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathyis) a small-vessel disease caused by loss of function mutaions of htrA1, which cleaves several extracellular matrix proteins. Here, we isolated microvessels from htra1 KO and wild type control mice to study the effect of htra1 loss of function on microvessels.