The U937 cell line, established from the pleural effusion of a patient with generalized histiocytic lymphoma in 1976, has become an essential cellular model in the field of immunology, particularly in studies related to monocyte and macrophage biology. U937 cells have contributed significantly to our understanding of cell differentiation, immune response, and the pathogenesis of diseases like leukemia.

The U937 cell line is extensively utilized in immunological and hematological research due to its remarkable ability to differentiate into monocyte or macrophage-like cells when treated with agents like retinoids, Vitamin D3, and phorbol esters such as TPA (12-O-Tetradecanoylphorbol-13-acetate). This differentiation capacity is crucial for studying various aspects of monocyte and macrophage biology, including phagocytosis, antigen presentation, and cytokine production.

Upon differentiation, U937 cells adopt functional characteristics akin to those of mature immune cells, making them an invaluable model for investigating the monocyte-endothelium adhesion process, a critical step in the immune response and inflammation. Moreover, these cells have been employed to delve into the complex regulation of inflammatory gene expression and the signaling pathways involved, particularly the NF-κB pathway.

U937 cells are also widely used in the study of apoptosis, or programmed cell death. These cells are particularly useful for investigating the molecular pathways leading to apoptosis, the effects of various stimuli or drugs on apoptotic processes, and the interplay between apoptosis and other cellular functions like cell cycle regulation and differentiation.

In summary, the U937 cell line serves as a versatile and relevant model for studying a wide range of biological processes, from cell differentiation and apoptosis and the effect of pharmacological agents.