BAY 61-3606 is primarily used in research settings as a selective inhibitor of SYK (spleen tyrosine kinase). It is widely applied in studies focusing on immune cell signaling pathways, particularly in understanding the role of SYK in autoimmune diseases, inflammation, and cancer. Researchers utilize it to investigate the mechanisms of B-cell receptor signaling and its impact on immune responses. Additionally, it serves as a tool in preclinical studies to evaluate potential therapeutic strategies targeting SYK-dependent processes in conditions like rheumatoid arthritis, lymphoma, and allergic reactions. Its application helps in identifying new drug targets and developing treatments for SYK-related disorders.