Abstract: Cancer associated fibroblast (CAF) is the most important component in the tumor environment, and some researchers even propose that CAF can be the new target in cancer therapy. However what make it difficult for researchers are the various origins of the CAF, such as resident fibroblast, epithelium, endotheliocyte, mesenchymal cell, stem cell and so on. The various origins define their different phenotypes and functions. Further understanding about the origins of the CAF will help us to explore a novel approach for cancer therapy.

Key words: Neoplasms, Cell differentiation, Cancer associated fibroblasts, Tumor microenvironment