NECTIN4 and in situ carcinoma: In comparison to NECTIN4 protein levels in normal urothelial samples (overall positivity: 62%, membranous positivity: 4%, median H-score: 25, IQR H-score: 55–0), NECTIN4 expression in non-invasive parts of CIS/T1HG and of pure TaHG/T1HG lesions was significantly enriched (for both comparisons P < 0.001), but not in HG tumors from mixed-grade papillary lesions (Table 2 and Fig. 1A).