TGFB1 and neoplasm: CAFs are one of the most abundant cell types in the tumor microenvironment, and in addition to being the main producer of fibrotic ECM proteins and collagens, CAFs have multiple immunosuppressive functions and secrete numerous chemokines, cytokines, and proteases, such as TGF-β, VEGF, CXCL12/CXCR4, interleukin-6, and matrix metalloproteinases (MMPs) [58, 63].