TAP1 (transporter 1, ATP binding cassette subfamily B member) is an essential component of the antigen presentation machinery that forms a heterodimeric complex with TAP2 to transport peptide antigens from the cytosol to the endoplasmic reticulum for loading onto MHC class I molecules 1. This ATP-dependent transporter alternates between inward-facing and outward-facing conformations during the transport cycle, preferentially selecting peptides of 8-13 amino acids with specific anchor residues 2. TAP1 serves as a critical molecular scaffold in the peptide loading complex essential for peptide-MHC class I assembly and antigen presentation 1. Genetic polymorphisms in TAP1 have been associated with increased susceptibility to several diseases, including type 1 diabetes mellitus 3, ankylosing spondylitis 4, and pulmonary tuberculosis 5. In cancer contexts, TAP1 plays complex roles in immune evasion. While TAP2 downregulation in non-small cell lung cancer reduces sensitivity to immunotherapy 6, TAP1 overexpression in EBV-associated gastric cancer promotes immune escape through JNK/STAT1/PD-L1 signaling 7. Mutations in TAP1 can cause MHC class I deficiency syndrome, characterized by recurrent sinopulmonary infections 8.