PLAUR and cancer: PLAUR is not uniformly expressed in tumors and its expression may occur only in a subset of tumor-associated cells.26 These caveats have been observed in other cancer types, which sometimes create a disconnect between gene expression and protein expression (e.g., immunohistochemistry) data in the same cancer type.27 Nevertheless, regardless of how PLAUR or uPAR expression is assessed, the differential expression between tumor and normal tissue is clearly evident.