Btk inhibitor 2 is primarily utilized in the field of medical research and therapeutics, particularly in the treatment of B-cell malignancies and autoimmune diseases. It functions by selectively inhibiting Bruton's tyrosine kinase (Btk), a key enzyme involved in B-cell receptor signaling. This inhibition disrupts the survival and proliferation of malignant B-cells, making it effective in conditions like chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenström's macroglobulinemia. Additionally, its role in modulating immune responses has shown promise in managing autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus. Researchers also explore its potential in addressing inflammatory diseases due to its ability to regulate immune cell activity.