His research has centered on defining the role of immune cells called macrophages in tumor progression. The focus of these studies has been to identify pathways of tumorigenesis critical to a variety of murine tumor types including lung carcinoma, melanoma, colon carcinoma and cutaneous squamous cell carcinoma. Parallel studies in identifying tumor-promoting pathways induced by infiltrating macrophages in human squamous cell carcinomas from immunosuppressed vs non-immunosuppressed patients is the current focus of the lab.