DOCK2-IN-1, an analogue of CPYPP, effectively inhibits DOCK2 (IC50 = 19.1 μM) by reversibly binding to its DHR-2 domain, thereby hindering its catalytic function. This compound obstructs the activation of Rac in lymphocytes, triggered either by chemokine or antigen receptors. Consequently, DOCK2-IN-1 markedly reduces chemotactic responses and T cell activation [1].