PD-L1 and FOXP3 expression in high-grade squamous intraepithelial lesions of the anogenital region
Host immunosurveillance is an important factor in the progression of high-grade squamous intraepithelial lesions (HSIL) into high-risk human papillomavirus (HR-HPV)-related squamous cell carcinoma. Immune escape by forkhead box protein P3 (FOXP3+) immunoregulatory T cells and the programmed death-ligand 1 (PD1/PD-L1) axis, mechanisms best described in the context of invasive neoplasms, may play a role in the evolution of pre-malignant lesions. This morphological study aimed to characterize the inflammatory response and expression of FOXP3 and PD-L1 in anal, vulvar, and penile HSILs and compare them with those in low-grade SILs co-infected with HR-HPV (LSIL