Human leukocyte antigens in the era of precision medicine in immunology.

HLA molecules play a crucial role in immune reactivity, influencing autoimmune diseases, transplantation immunology, susceptibility to infectious diseases, drug hypersensitivity, and personalized medicine. Here, we highlight the transformative impact of HLA research on transplantation immunology, personalized medicine, and immunotherapeutic development by summarizing fundemental concepts, challenges in HLA-based interventions, and recent technological innovations and future directions. HLA research has significant theoretical and practical implications to characterize the immune response and transplant compatibility. Although the HLA system is seen as a barrier to transplantation, in the era of precision medicine, HLA has become the master key to unlocking personalized immunotherapy, predicting drug toxicities, and engineering the next generation of cancer vaccines.