CMV infection is also closely related to increased production of the proinflammatory cytokine IL-15, which also activates T cells, enhances mitochondrial activity, and promotes the intracellular accumulation of cytolytic molecules such as GzB and perforin, as shown in our studies and in those of others [91, 101, 140-142]. This evidence concerns the gene PRF1 and cytomegalovirus infection.