Protein atlas of fibroblast specific protein 1 (FSP1)/S100A4.

Fibroblast specific protein 1 (FSP1)/S100A4 is a calcium binding protein which has been linked to epithelial-mesenchymal transition, tissue fibrosis, pulmonary vascular disease, metastatic tumour development, increased tumour cell motility and invasiveness. This protein is reported to be also expressed in newly formed and differentiated fibroblasts and has been used in various studies to demonstrate epithelial-mesenchymal transition (EMT). We aimed to characterize S100A4 positive cells in different human tissue compartments, with the focus on fibroblasts/myofibroblast.