KRT5 and urothelial carcinoma: CK5/6 is a basal cytokeratin, which is expressed in urothelial carcinoma and positivity signifies adverse prognostic features such as high-grade and muscularis propria invasion.[14] Moreover, Woo et al utilized whole-genome mRNA expression profiling and hierarchical cluster analysis to show that the basal MIBC were significantly enriched with squamous features and expressed basal biomarker mRNA, such as CK5/6, at higher levels.