The exosome secretion eliminates harmful cytoplasmic DNA from cells. The inhibition of exosome secretion causes the cytoplasmic accumulation of nuclear DNA, thereby causing the activation of STING, the cytoplasmic DNA sensing machinery. This event provokes the innate immune response, such as type I IFN pathway, leading to the elevation of the intracellular levels of ROS. In turn, this activates the DDR in normal human cells. This machinery may also play keys role in preventing viral hijacking of host cells by excreting viral DNA from cells.