FAP and cancer: Fibroblasts are the main cells of the tumour mesenchyme that can be induced by cancer cells to become Cancer-Associated Fibroblasts (CAF), and these fibroblasts usually express cytoskeletal proteins (α-SMA) or fibroblast activation proteins (FAP), and it is now proposed that CAFs can establish an immune-suppressing by interacting with the TME components and thus establishing an immune-suppressive microenvironment (40).