Homo sapiens HBI-61 snoRNA. This H/ACA box RNA was cloned by Gu et al. (2005) from blood cells by an RT-PCR method that preferentially amplifies H/ACA box snoRNAs. Its expression was evidenced by Northern blot. Its mouse orthologue was cloned by Hüttenhofer et al. (2001) and named MBI-61.HBI-61 is predicted to guide the pseudouridylation of 28S rRNA U4606 (Schattner et al., 2006). The modification of this position was experimentally established (Ofengand and Bakin, 1997). The H/ACA box snoRNAs HBI-61, E3 and ACA4 and the C/D box snoRNA snR39B share the same host gene.