NECTIN4 and in situ carcinoma: Of note, while NECTIN4 inter-lesional heterogeneity was relatively low in patients with multifocal CIS/T1HG and patients with multifocal pure TaHG/T1HG tumors, a higher degree of NECTIN4 heterogeneity was observed in patients with multifocal TaHG tumors from mixed-grade lesions.