UPK3A and neoplasm: Taken together, these results show that regulatory factors accurately identify Uro‐diff‐positive tumours at both the mRNA level and the protein level, but, whereas KRT20 and UPK3 mRNA expression overlaps with the Uro‐diff signature, only subsets of the tumour cells are positive at the IHC level, and expression patterns are inconsistent with the proteins' structural functions in normal differentiation.