ZFAS1 and head and neck squamous cell carcinoma: Meanwhile, in breast cancer, head and neck squamous cell carcinoma (SCC) low expression level of U44 directly correlated with poor survival of patients [37, 47]. ZFAS1 contains three box С/D RNAs: SNORD12, SNORD12B, and SNORD12C, that guide 2′-O-methylation of G3878 in 28S rRNA. ZFAS1 locus and these snoRNAs were shown to be strongly downregulated in breast ductal carcinoma [49].