Horizontal mitochondrial transfer and the tug-of-war between cancer cells and immune cells

Horizontal mitochondrial transfer (HMT) is an emerging field of cell biology. Since its discovery, HMT has been extensively studied in the context of cancer due to the essential role of mitochondria in fueling the proliferation of tumor cells. The role of HMT in cancer, however, reaches far beyond a simple mechanism of organelle acquisition. Indeed, several recent studies have demonstrated HMT from cancer to immune cells and vice versa, with a profound impact on antitumor immune responses and potentially on immunotherapy efficacy. In this opinion article, we propose that HMT should receive attention as another modulatable mechanism of the functional tug-of-war between cancer and immune cells, further contributing to the complexity of the tumor microenvironment and likely sculpting the outcome of competition between the two teams of cells.