FAP and atherosclerosis: While recent data has emerged suggesting Fsp-1 is not entirely specific for fibroblasts30, by immunofluorescence confocal microscopy, compared with Fap staining, we identified a similar number of Fsp-1+ cells that co-expressed Yfp (Supplementary Fig. 5; Supplementary Movie 2), supporting the occurrence of EndMT in atherosclerosis.