LHFPL5 is an auxiliary subunit of the mechanotransducer (MET) ion channel complex essential for auditory and vestibular function. It localizes to the tips of shorter stereocilia in cochlear hair cells, where it functionally couples the tip-link protein PCDH15 to the transduction channel pore 1. LHFPL5 physically interacts with and stabilizes the core channel protein TMC1, with mutations disrupting this binding and destabilizing TMC1 expression 2. The PCDH15-LHFPL5 complex forms a 2-fold symmetric assembly where LHFPL5 stabilizes PCDH15 transmembrane helices and transmits stereociliary deflection forces to open the MET channel 1. LHFPL5 works alongside other auxiliary proteins including TMIE, CIB2, and TOMT to maintain channel complex positioning at the tip link 3. Biallelic loss-of-function variants in LHFPL5 cause autosomal recessive nonsyndromic hearing impairment (DFNB67), with identified mutations including frameshift deletions, missense variants, and splice site alterations 45. LHFPL5 dysfunction also causes bilateral vestibular dysfunction alongside deafness 6, indicating its critical role in both auditory and vestibular mechanotransduction.