TWS119 is primarily used in stem cell research and regenerative medicine due to its ability to modulate key signaling pathways involved in cell differentiation. It acts as a selective inhibitor of glycogen synthase kinase-3 (GSK-3), particularly the GSK-3β isoform, which plays a critical role in the Wnt signaling pathway. By inhibiting GSK-3β, TWS119 promotes the stabilization of β-catenin, leading to the activation of downstream genes that support the self-renewal and maintenance of pluripotent stem cells. One of the major applications of TWS119 is in the directed differentiation of embryonic and induced pluripotent stem cells into specific lineages, such as neurons. It has been shown to enhance the generation of neural precursor cells and mature neurons, making it a valuable tool in neuroscience research and in developing models for neurodegenerative diseases. Additionally, TWS119 has been explored in cancer research due to the involvement of GSK-3 in cell proliferation and apoptosis. Its regulatory effect on Wnt and other signaling pathways provides insight into tumor development and potential therapeutic strategies. Overall, TWS119 is a powerful small molecule tool for controlling cell fate in experimental biology, with broad utility in drug discovery, disease modeling, and the development of cell-based therapies.