FABP5 (fatty acid binding protein 5) is an intracellular carrier protein that transports long-chain fatty acids and related lipids, including endocannabinoids, within cells 1. The protein facilitates cytosolic transport and selectively delivers specific fatty acids from the cytosol to the nucleus, where they activate nuclear receptors such as peroxisome proliferator-activated receptor gamma (PPARγ) 23. FABP5 directly binds to the regulatory-associated protein of mTOR (Raptor) to enhance mTORC1 formation and signaling, ultimately promoting cellular proliferation in response to dietary ω-6 linoleic acid 3. In disease contexts, FABP5 plays significant roles in inflammation and cancer. It mediates keratinocyte-driven neutrophil recruitment in psoriasis through interaction with valosin-containing protein (VCP) and NF-κB signaling activation 4. FABP5 also promotes Th17 cell differentiation and intestinal inflammation through lipid metabolism regulation 5. In hepatocellular carcinoma, FABP5+ tumor-associated macrophages exhibit enhanced immunosuppressive properties via the FABP5-PPARγ pathway, contributing to tumor progression and reduced immunotherapy efficacy 2. FABP5 is identified as a crucial factor for both normal gastric stem/progenitor cells and gastric cancer cells 6, highlighting its dual roles in tissue homeostasis and pathology.