Based on these results, our hypothesis is that when CD44, and, to a lesser extent, also CK5/6, is expressed by tumor cells in pT2 UC, it has an intrinsic power to stratify patients with the best outcome, regardless of luminal vs. basal subdivision, obtained with our score analysis (some of our luminal cases also express CD44; see Table 3). Here, KRT5 is linked to neoplasm.