The Btk inhibitor 1 R enantiomer is primarily used in the field of medical research and drug development, particularly in the treatment of autoimmune diseases and certain types of cancers. It functions by selectively inhibiting Bruton's tyrosine kinase (Btk), an enzyme crucial for the development and function of B cells, which play a significant role in the immune response. By blocking Btk, this compound helps to modulate the immune system, reducing inflammation and the progression of diseases like rheumatoid arthritis, lupus, and multiple sclerosis. Additionally, its application in oncology is notable, as it can hinder the growth of B-cell malignancies such as chronic lymphocytic leukemia and mantle cell lymphoma. The R enantiomer form is specifically chosen for its enhanced efficacy and reduced side effects, making it a valuable component in targeted therapy.