Function and characteristics of TIM-4 in immune regulation and disease (Review)

T-cell/transmembrane immunoglobulin and mucin domain containing 4 (TIM-4) is a phosphatidylserine receptor that is mainly expressed on antigen-presenting cells and is involved in the recognition and efferocytosis of apoptotic cells. TIM-4 has been found to be expressed in immune cells such as natural killer T, B and mast cells and to participate in multiple aspects of immune regulation, suggesting that TIM-4 may be involved in a variety of immune-related diseases. Recent studies have confirmed that TIM-4 is also abnormally expressed in a variety of malignant tumor cells and is closely associated with the occurrence and development of tumors and the tumor immune microenvironment. The present study aimed to describe the expression and functional characteristics of TIM-4 in detail and to comprehensively discuss its role in pathophysiological processes such as infection, allergy, metabolism, autoimmunity and tumor immunity. The current review provided a comprehensive understanding of the functions and characteristics of TIM-4, as well as novel ideas for the diagnosis and treatment of diseases.