Finally, cdc2-like kinase 1 (CLK1), one of the four isoforms conforming an evolutionary conserved group of dual-specificity kinases, is related with AD by phosphorylating the serine residues in arginine-rich (SR) proteins [2,3,5,6,7,8,9,10,11,12,13,14,15]. The gene discussed is CLK1; the disease is Alzheimer disease.