He Y, et al. - Researchers systematically retrieved studies from the relevant databases (Web of Science, PubMed, Cochrane Library and Embase) to examine the prognostic value of ki67 as a marker in patients with non-muscle invasive bladder cancer (NMIBC) treated with BCG. They identified the overexpression of ki67 to be the risk factor for progression-free survival (PFS). In patients with NMIBC treated with BCG intravesical immunotherapy, the relationship between the expression of ki67 and recurrence-free survival was not statistically significant.