Liu Y, et al. – In this retrospective study, researchers investigated the predictive value of biomarker P16^INK4a for progression risk of anal low-grade squamous intraepithelial lesions (LSILs). They performed surveillance high-resolution anoscopy and biopsy on 109 HIV-infected and 18 HIV-uninfected individuals with biopsy-confirmed anal LSIL at initial screening within 2 years of diagnosis. Performing P16 immunohistochemistry on index lesions, they identified biomarker P16 to be the strongest predictor for anal LSIL-to-high-grade squamous intraepithelial lesion progression, outperforming other risk factors. Hence, they recommend using P16 immunohistochemistry to help stratify patients at high vs low risk of progression to improve the overall effectiveness of surveillance.