FasL is a 40 kDa type-II transmembrane protein also known as CD178 or TNSF6. FasL plays a crucial role in the development, homeostasis, and function of the immune system due to its ability to induce apoptosis in target cells by binding to its receptor Fas/CD95 on adjacent cells. Because of this apoptotic property, FasL may be a protein of interest for cancer research.