Stefano Garofalo, PhD. Reasercher. In last few years, my research mainly focused on the interaction between the CNS and peripheral immune cells. I started dealing with infiltrating immune cells in the brain since my Ph.D. at the Sapienza University of Rome. I studied the interactions between immune cells, glia and the microenvironment of brain tumors, focusing on the effect of environmental stimuli on Natural Killer (NK) cell recruitment and microglia phenotype. Exploring the underlying mechanisms, I demonstrated a virtuous cycle starting with the production of interleukin (IL)-15 by microglial cells that, in turn, stimulates NK cells to produce IFN-g, with effects on microglia phenotype.