LRRN2 (leucine rich repeat neuronal 2) is a plasma membrane protein with signaling receptor activity involved in cell adhesion and signal transduction 1. The protein appears to play diverse roles across multiple biological contexts. In cancer, LRRN2 functions as a tumor suppressor in colon adenocarcinoma, where decreased expression is associated with poor prognosis 1. Additionally, LRRN2 can be involved in oncogenic ALK fusion events in lung adenocarcinoma, contributing to tumorigenesis 2. In liver transplantation, elevated LRRN2 expression serves as a biomarker for graft quality, with upregulated expression being an independent risk factor for graft failure 3. Neurologically, LRRN2 has been implicated in essential tremor susceptibility through genome-wide association studies, with functional analyses suggesting involvement in cerebellar pathways and axonogenesis 4. The gene also shows tissue- and sex-specific DNA methylation patterns, particularly in the hippocampus, suggesting roles in neurodevelopment and sex-specific brain functions 5. Furthermore, LRRN2 has been identified as a host factor potentially involved in SARS-CoV-2 infection through CRISPR screening studies 6. These findings indicate LRRN2's multifaceted roles in cellular signaling, disease pathogenesis, and organ-specific functions.