Chinn Z, et al. - This study was designed to evaluate the association between PD-L1 and the immunoregulatory enzyme indoleamine dioxygenase 2,3 (IDO) expression by evaluating 65 cases of cervical and vulvar intraepithelial neoplasia and squamous cell carcinomas (SCC) for IDO and PD-L1 expression. Researchers reported that IDO and PD-L1 co-expression was frequent in cervical SCCs and vulvar SCCs, to a lesser extent, and suggested a role for combination immunotherapy in a subset of cervical SCCs and select vulvar SCCs. In intraepithelial lesions, expression for both markers was less common. In the absence of invasion, this investigation does not support this form of immunotherapy.