POLE and urinary bladder cancer: Interestingly, a recent report showed that, in bladder cancer cell lines, TRPV1-mediated extracellular Ca2+ entry prevented the nuclear translocation of proliferating cell nuclear antigen (PCNA), a 29 kDa protein which serves as auxiliary protein for accessory protein for DNA polymerase δ (Polδ) and DNA polymerase ε (Polε) [110,111].