ADAP plays a pivotal role in CD4+ T cell activation but is only marginally involved in CD8+ T cell activation, differentiation, and immunity to pathogens.

The adhesion and degranulation promoting adaptor protein (ADAP) is a multifunctional scaffold involved in many different signaling pathways that are important for the function of T cells, including the inside-out and outside-in signaling of integrins, the activation of NF-κB, and the subsequent production of proinflammatory cytokines (e.g., IFN-γ and IL-2).