Tap1, also known as Antigen Peptide Transporter 1, is a member of the ATP-binding cassette (ABC) family. It is crucial for transporting antigen peptides from the cytoplasm to the lumen of the endoplasmic reticulum, and then loading them onto major histocompatibility complex (MHC) class I molecules, thus playing a significant role in the immune response and antigen presentation [5].

Tap1 has been associated with multiple diseases. In ankylosing spondylitis, specific polymorphisms in Tap1 (Tap1-333Val, Tap1-637Gly) were likely to be associated with the disease, especially when compared with HLA-B27-negative controls [1]. In uveal melanoma, upregulated Tap1 was associated with shorter survival, higher metastasis likelihood, and higher mortality, and in vitro silencing of Tap1 inhibited cell proliferation and metastasis [2]. In gastric cancer, Tap1 was identified as a T-cell related therapeutic target, and oxaliplatin could enhance immunotherapy by promoting Tap1 expression [3]. In colorectal cancer, down-regulation of Tap1 was a mechanism of tumor immune escape and a poor prognostic factor [4]. In pancreatic cancer, Tap1 promoted resistance to MEK inhibitors, and suppressing Tap1 sensitized resistant cells to the inhibitor [6]. In gastric carcinoma, TAP1 expression was positively correlated with various immunological traits and patients with high TAP1 expression were more likely to achieve complete remission after immunotherapy [5]. In locally advanced gastric cancer, high Tap1 expression was associated with better overall survival [7]. In a study with Apoe⁻/⁻Tap1⁻/⁻ mice, Tap1-deficiency did not alter atherosclerosis development, indicating a minor role for CD8⁺ T cells and Tap1-dependent antigen presentation in this disease process [8].

In conclusion, Tap1 is essential for antigen presentation and immune response. Studies, especially those using gene-knockout mouse models like Apoe⁻/⁻Tap1⁻/⁻ mice, have revealed its diverse roles in multiple diseases, including autoimmune diseases, cancers, and atherosclerosis. These findings contribute to a better understanding of disease mechanisms and may provide potential therapeutic targets.