LSAMP (limbic system associated membrane protein) is a GPI-anchored cell adhesion molecule of the IgLON family that mediates selective neuronal growth and axon targeting in the limbic system 1. The protein functions as a homo- or heterodimer capable of heterophilic cell-cell interactions critical for neurite outgrowth, axonal fasciculation, and synapse formation 1. LSAMP is essential for normal hippocampal mossy fiber projection development and contributes to remodeling of mature neural circuits. Recently, LSAMP was identified as a negative regulator of myelination, with cell-type-specific expression in neurons 2. Mechanistically, LSAMP interacts dynamically with AMPA receptors during synaptic plasticity, influencing surface receptor mobility in dendritic spines 3. Loss of LSAMP function impairs GABAergic signaling, with Lsamp-deficient mice showing hyperactivity, decreased anxiety, and altered GABAA receptor subunit balance 4. Clinically, LSAMP polymorphisms associate with schizophrenia, major depressive disorder, and panic disorder 56. LSAMP functions as a candidate tumor suppressor, with deletions and methylation-mediated silencing identified in osteosarcomas correlating with poor survival 7. These findings establish LSAMP as a multifunctional regulator linking neural circuit development to psychiatric and oncologic disease.