 As an immunologist, he has contributed significantly to the understanding of lymphocyte activation and its implication in autoimmune diseases.He identified some of the mechanisms involved in cytokine- and chemokine-activated signaling pathways and their relevance in HIV-1 infection, cell migration and cancer.Today he is interested in stem cell biology, specifically in the molecular mechanisms that control self-renewal vs. differentiation of these cells, and their implication for cancer, regenerative medicine and inflammation.