CLK4 and prostate cancer: For example, SM08502 (Cirtuvivint), which inhibits CLK4, showed efficacy across 17 colorectal cancer (CRC) cell lines and inhibited the proliferation of six human gastric cancer cell lines with various mutations.[16] Furthermore, it exhibited significant tumor growth inhibition in xenograft models of CRC and gastric cancer.[16] In addition, TG003, a discovery‐stage compound, showed anticancer activity in prostate cancer cells and altered splicing of cancer‐related genes.[17] However, existing drugs often exhibit off‐target activity, which can increase the risk of adverse effects.