POU5F1 and cholangiocarcinoma: However, our recent publications demonstrated that DNA lesions (8-oxodG and 8-nitroguanine) were formed in CSCs that had Oct3/4 expression in S. haematobium-associated bladder cancer, and CD133, Oct3/4, oval marker 6 (OV6) and CD44 expressions in O. viverrini-associated cholangiocarcinoma [121].