Homo sapiens C/D box snoRNA HBII-437. This snoRNA was discovered by computer aided search of conserved sequences and structural motifs in the Prader-Willi locus (15q11-q13). However, its expression could not confirmed by Northern blot analysis. HBII-437 (as well as HBII-438A/B, HBII-13, HBII-436 and the two clusters of HBII-85 and HBII-52 snoRNAs) is encoded in an intron of the large (460kb), paternally expressed, transcription unit (SNURF-SNRNP-UBE3A AS), that is antisense to the maternally expressed UBE3A gene. This snoRNA, which harbors a degenerated D box, has no identified RNA target.