In research on nucleotide anabolism in cholangiocarcinoma, CDC like kinase 3 (CLK3) was found to activate the rate-limiting enzyme in de novo purine anabolism, ATIC, by regulating the USP13/Fbxl14/c-Myc signaling axis, thereby promoting the molecular progression of cholangiocarcinoma. The gene discussed is USP13; the disease is cholangiocarcinoma.