Abstract
Cancer immunotherapies leverage the immune response to target cancer cells with T cells playing a pivotal role. However, tumor microenvironments often harbor immune suppressive elements hindering T cell function. This chapter describes in vitro T cell stimulation assays analyzing proliferation, inhibitory marker expression, and effector functions to assess the impact of immune suppression on T cell responses. These assays also evaluate the efficacy of immunotherapeutic interventions in overcoming immune suppression and enhancing anti-tumor immunity, thereby unraveling the intricate T cell-tumor microenvironment dynamics for more effective cancer immunotherapies.