MIGA1 (mitoguardin 1) is a mitochondrial outer membrane protein that regulates mitochondrial fusion and cellular metabolism. MIGA1 functions by forming homo- and heterodimers at the mitochondrial outer membrane and facilitating PLD6/MitoPLD dimer formation, thereby promoting mitochondrial fusion 1. Loss of MIGA1 results in fragmented mitochondria, while overexpression induces mitochondrial clustering and fusion 1. Beyond mitochondrial morphology, MIGA1 regulates cell proliferation through multiple signaling pathways. In ovarian granulosa cells, MIGA1 promotes proliferation by activating AKT and modulating Hippo-YAP1 signaling, with downstream implications for reproductive endocrine diseases like PCOS 2. In adipocytes, MIGA1 downregulation impairs mitochondrial function, reducing oxygen consumption and UCP1 expression, suggesting roles in metabolic regulation and fat distribution 3. Clinically, MIGA1 has emerging disease relevance: rare loss-of-function variants in MIGA1 are associated with high-grade serous ovarian cancer susceptibility 4. Additionally, MIGA1 was identified as a hub gene in colorectal cancer networks 5, though the specific functional significance in cancer requires further investigation. These findings position MIGA1 as a multifunctional regulator linking mitochondrial dynamics to metabolic homeostasis and reproductive health.