Horizontal mitochondrial transfer: an emerging field in cell biology.

The field of horizontal mitochondrial transfer (HMT), also referred to as intercellular mitochondrial transfer, has recently gained momentum due to an increasing number of publications that go well beyond diseases such as cancer. From co-culture experiments to in vivo evidence in mouse cancer models, noncancerous diseases, and normal tissue and organ homeostasis and development, it is becoming increasingly clear that HMT is a fundamental physiological phenomenon broadly relevant to complex organisms. Recent methodological advances, epitomized by ultra-high-resolution microscopy and spatial and single-cell multiomics technologies, allow for research that strongly supports HMT as an emerging area of cell biology.