SLC36A2 (PAT2) is an electrogenic proton/amino acid symporter located on chromosome 5, primarily expressed at the apical surface of the renal proximal tubule 1. It selectively transports small side-chain amino acids including glycine, alanine, and proline in both L- and D-enantiomeric forms, with higher substrate affinity (Km 0.1-0.7 mM) than its family member SLC36A1 1. SLC36A2 is essential for amino acid reabsorption in the kidney; mutations result in iminoglycinuria and hyperglycinuria—rare autosomal recessive and semidominant disorders characterized by excessive urinary glycine and imino acid excretion 2. These conditions are clinically significant as they associate with osteoporosis, early-onset osteopenia, and renal calculi formation 3. Beyond its primary renal function, SLC36A2 expression is also found in bone and muscle tissues 4, and emerging evidence suggests roles in diverse pathological contexts; genomic analyses identified SLC36A2 as a potential biomarker and therapeutic target in vestibular schwannoma and oral squamous cell carcinoma 56. The transporter can be inhibited by certain tryptophan derivatives, providing experimental tools for investigating its physiological functions 7.