CLDN4 and vulvar intraepithelial neoplasia: Other claudins tested did not show significantly different expression between the groups; within this study cohort, they showed positive expression in VSCC in 66.7% (claudin 3 and claudin 4) to 86.7% (claudin 1).10 Following on from this, Riski et al. examined the expression of different claudin members (1, 3 M, 3S, 4, 5 and 7) in precancerous vulvar lesions (vulvar intraepithelial neoplasia, VIN) and VSCC (n = 49) taking into account both membranous and cytoplasmatic staining patterns.