TG003 is primarily used as a selective inhibitor of the CDC2-like kinase 1 (CLK1) enzyme, making it a valuable tool in biochemical and pharmacological research. It is commonly applied in studies related to RNA splicing, where CLK1 plays a key role in phosphorylating serine/arginine-rich (SR) proteins involved in spliceosome assembly. By modulating this pathway, TG003 helps researchers investigate alternative splicing mechanisms, which are critical in understanding gene expression and the development of diseases such as cancer and neurodegenerative disorders. Additionally, TG003 has been utilized in cell-based assays to explore the functional consequences of splicing dysregulation and to assess potential therapeutic targets in oncology and virology. Its specificity and cell permeability make it suitable for in vitro experiments aimed at dissecting kinase signaling networks.