They reported different staining intensities within neoplastic affections, especially for claudin 3 M in VIN I lesions, VIN II–III lesion and invasive carcinomas (p = 0.026; Kruskal–Wallis test) as well as a decreased expression of claudin 3 M in carcinomas compared to low-grade intraepithelial neoplasia (p = 0.002; Mann–Whitney test). Here, CLDN3 is linked to invasive carcinoma.