RecruitingDiagnostic testScreening Strategies Among High-risk Populations for Anal CancerThe goal of the proposed research is to 1) examine the performance of emerging screening methods for anal high-grade squamous intraepithelial lesion (aHSIL), a precancerous condition of anal cancer, among populations at high risk for anal cancer and 2) characterize DNA methylation, immunologic response, and environmental factors associated with aHSIL.