MINAR2 (membrane integral NOTCH2-associated receptor 2) is a multifunctional protein with critical roles in hearing, neurological function, and metabolic homeostasis. Primarily, MINAR2 regulates cholesterol distribution and homeostasis, particularly in hair cell bundles of the inner ear, where it localizes to lysosomes and recruits cholesterol to ensure proper mechanotransduction 1. Loss-of-function mutations in MINAR2 cause autosomal recessive nonsyndromic deafness characterized by stereocilia defects, hair cell degeneration, and progressive sensorineural hearing loss in both humans and mice 2. Mechanistically, MINAR2 interacts with the NOTCH2 signaling pathway and localizes to endoplasmic reticulum compartments 3. Beyond auditory function, MINAR2 acts as a negative regulator of mammalian TOR complex 1 (mTORC1) through interaction with Raptor, controlling cellular metabolism and adipocyte homeostasis 4. MINAR2 deficiency results in mTOR hyperactivation, leading to obesity and impaired glucose tolerance. Additionally, MINAR2 loss causes Parkinson's disease-like motor symptoms in mice, including dopaminergic neuron loss and α-synuclein accumulation, with reduced expression documented in Lewy body dementia patients 3. These findings establish MINAR2 as essential for auditory function, neuronal homeostasis, and metabolic regulation, with implications for neurodegenerative and metabolic disorders.