FABP5,also named as PA-FABP and E-FABP,belongs to the calycin superfamily and Fatty-acid binding protein (FABP) family. It is high specificity for fatty acids. FABP5 is highest affinity for C18 chain length. It may be involved in keratinocyte differentiation. FABP5 is a fatty acid-binding protein and is expressed in epidermis and endothelial cells of the microvasculature of different organs. FABP5 has also been identified as a tumor-associated antigen,which is highly expressed in various cancers. FABP5 was detected in the sera of HNSCC patients with early stage cancer. Antibodies specific for FABP5 were significantly increased in a substantial amount in patients,suggesting that FABP5 may be a potential diagnostic biomarker for HNSCC. FABP5 may serve as a biomarker for HNSCC.