His interests run the entire spectrum of neoplasms of the urogenital tract. He is the leader of the Genitourinary Pathology Team at Memorial as well as Director of the Genitourinary Pathology Subspecialty Fellowship that has existed uninterrupted at his institution since 1991. He has directed the genitourinary pathology research laboratory at Memorial Sloan Kettering Cancer Center since 1992, focusing primarily in biomarker characterization and validation.