Cell-permeable. A potent, specific, reversible, and ATP-competitive inhibitor of Cdc2-like kinase (Clk) (Ki = 10 nM for mClk1/Sty; IC₅₀ = 20 nM, 200 nM, >10 µM, and 15 nM for mClk1, mClk2, mClk3, and mClk4, respectively). Recently, it has been shown that TG003 promotes the skipping of exon 31 in the endogenous dystrophin gene in a dose-dependent manner and increases the production of the dystrophin protein.