Bladder cancer and TILs. (A) Urothelial carcinomas can be classified as pTa (papillary), pT1 (lamina propria invasion), pT2 (muscle invasive), pT3 (invasion to perivesical fat), and pT4 (locally advanced). (B) Interaction of FasL on tumor cells and Fas-positive T-lymphocytes leads to elimination of Fas-positive TILs, which appears to be a caspase-mediated event.