MICU2 functions as a calcium sensor protein that regulates the mitochondrial calcium uniporter (MCU) channel through its EF-hand domains 1. MICU2 forms a disulfide-linked heterodimer with MICU1 that controls MCU activity in a calcium-dependent manner 12. At low calcium concentrations, the MICU1-MICU2 complex inhibits calcium uptake by occluding the MCU pore, while at higher calcium levels, calcium binding induces conformational changes that move the heterodimer away from the pore, allowing calcium permeation 1. MICU2 exhibits calcium-dependent oligomerization, existing as a monomer in calcium-free conditions but forming dimers upon calcium binding 2. The protein plays crucial roles in cardiac calcium signaling, with overexpression enhancing mitochondrial calcium uptake and leading to cardiac hypertrophy 3. MICU2 is particularly important during neurodevelopment, being present in the developing brain but disappearing upon maturation 4. Loss of MICU2 causes neuronal overmigration and behavioral changes in young mice, and is linked to neurodevelopmental disorders in patients 4. In cancer, MICU2 upregulation promotes tumor aggressiveness and metabolic reprogramming in colorectal cancer 5. These findings establish MICU2 as a critical regulator of mitochondrial calcium homeostasis with significant implications for cardiac function, neurodevelopment, and cancer progression.