KLHL41 (kelch like family member 41) is a ubiquitin ligase adaptor protein critical for skeletal muscle sarcomere maintenance and integrity. As a component of the Cul3-RING ubiquitin ligase complex, KLHL41 stabilizes sarcomeric proteins through nonproteolytic ubiquitination, particularly preventing aggregation and degradation of Nebulin, an essential sarcomere component 1. This stabilization function is distinct from canonical protein degradation pathways and represents a unique molecular chaperone-like mechanism for protein preservation 1. KLHL41 also regulates myoblast proliferation and differentiation during skeletal muscle development and participates in myofibril assembly by promoting lateral fusion of thin fibrils into mature myofibrils. Mutations in KLHL41 cause nemaline myopathy 9, a fatal muscle disorder characterized by sarcomere disarray and lethal disruption of muscle structure 1. KLHL41 mutant mice display aberrant expression of muscle structural and contractile proteins mimicking human disease phenotypes 1. Recent evidence indicates KLHL41 is upregulated during beta2-adrenergic-mediated muscle hypertrophy and is required for the anabolic response to beta2-agonists in cultured myotubes 2, suggesting therapeutic potential for muscle wasting conditions. Homozygous KLHL41 mutations have been identified in critically ill neonates with nemaline myopathy 3, confirming its clinical relevance in severe early-onset myopathies.