In addition, the multistep logistic regression model, which included investigated basal and superficial markers (CK5/6, CD44, CK20), as well as group, localization, and pathological characteristics, showed that alteration of CK20 was not determined by expression of CD44 and CK5/6 and the phenotypic characteristics of UTUC and the groups (BEN and control UTUC). This evidence concerns the gene KRT5 and Balkan nephropathy.