The focus of my current research is intercellular communication both in healthy organisms and under conditions of infections and cancer. There is a large body of evidence demonstrating that, in addition to conventional receptor-ligand interactions, cells of the immune system can communicate with each other and with other cells of the organism through intercellular transfer of molecules and even organelles. The in vivo functional significance of these processes remains largely unexplored. The main questions are what information is shared, and how this affects cellular functions. We are using various transgenic and knockout mice and in vivo tumor mouse models to find the answers.