OBP2A (odorant binding protein 2A) is a lipocalin family member located on chromosome 9 that binds and transports small hydrophobic volatile molecules with high affinity for aldehydes and fatty acids 1. Primary expression occurs in epidermal keratinocytes, nasal structures, salivary glands, and genital tissues 1. Beyond olfactory function, OBP2A serves critical roles in barrier protection and tissue homeostasis. In skin, OBP2A protects epidermal keratinocytes against cytotoxic aldehydes and lipids by regulating lipid metabolism and preventing endoplasmic reticulum stress; OBP2A expression is markedly reduced in atopic dermatitis lesions and suppressed by interleukin-13 2. In prostate cancer, tumor-derived OBP2A promotes castration resistance by binding survival factors (CXCL15/IL8) and enhancing myeloid-derived suppressor cell infiltration; OBP2A inhibition combined with α-pinene treatment suppresses castration-resistant disease development 3. OBP2A also facilitates fatty acid secretion through the secretory pathway 4. Functionally, OBP2A contributes to odorant solubilization and olfactory mucus homeostasis, though human OBP2A's indispensability remains unclear as other lipocalins may compensate 5. Genetic variants in OBP2A have been identified as potential phenotype-modifying factors in inherited periodontal diseases 6, establishing OBP2A as a multifunctional protein relevant to skin health, cancer progression, and systemic disease.