Homo sapiens C/D box snoRNA U46. This snoRNA was cloned from HeLa cells by Kiss-Laszlo et al. (1996). It was independently found by a bioinformatics approach, and named U40, by Nicoloso et al. (1996). It is predicited to guide the 2'O-ribose methylation of 28S rRNA A3739. U46/U40 shares the same host gene with the C/D box snRNAs U39/U55, U38A and U38B (RPS8).