ABCA13 (ATP binding cassette subfamily A member 13) is a large membrane transporter protein that mediates cholesterol and ganglioside transport from the plasma membrane to intracellular vesicles through ATP-dependent mechanisms 1. The protein facilitates cholesterol internalization via endocytic retrograde transport and participates in synaptic vesicle endocytosis in cortical neurons, requiring its long N-terminal region and ATP hydrolysis for function 1. ABCA13 is predicted to be the largest ABC protein, consisting of 5058 amino acids, though alternative shorter isoforms have been proposed 23. The gene shows highest expression in human trachea, testis, and bone marrow 2. ABCA13 dysfunction is significantly associated with psychiatric disorders, including schizophrenia, bipolar disorder, and major depression 456. Rare coding variants in ABCA13 contribute to disease susceptibility with population attributable risks of 2.2% for schizophrenia and 4.0% for bipolar disorder 4. Additionally, ABCA13 amplification has been identified in gastric adenocarcinoma, where it associates with lymph node metastasis and advanced staging 7. These findings highlight ABCA13's critical role in neuronal cholesterol homeostasis and its clinical significance in both psychiatric and oncological contexts.