Notes: 2′-O-Methyluridine is a modified nucleoside that has been found in T. thermophila tRNA.{65558} Incorporation of 2′-O-methyluridine into siRNA targeting the gene encoding apolipoprotein B (ApoB) decreases ApoB protein levels in HepG2 cells and prevents the production of IFN-α in isolated human peripheral blood mononuclear cells (PBMCs) compared with siRNA containing only native nucleosides.{65559} Serum levels of 2′-O-methyluridine are decreased in patients with breast cancer.{65560}