Cecilia Yeung, MD, Fred Hutchinson Cancer Research Center, Seattle, WA, discusses the analysis of tumor microenvironment infiltrating immune cells, including the different techniques to characterize them, such as multiplex immunohistochemistry panels to help look at various tumor microenvironment infiltrates. Additionally, the CODEX platform, which contains several markers that can be tested simultaneously on a single slice of tissue, is also available to help characterize the complexities of the tumor microenvironment. This interview took place during the 36th Society for Immunotherapy of Cancer (SITC) Annual Meeting in Washington, D.C.