Host gene features vary considerably between snoRNA expression statuses. (A–D) Proportion of snoRNAs per expression status for C/D (left panel) and H/ACA box snoRNAs (right panel) according to their genomic context (A), their host gene function (B), promoter type (C), and sensitivity to nonsense-mediated decay (NMD) (D). (A) Fisher's exact test; (***) P < 5 × 10−6 and (***) P < 2 × 10−32, respectively, for C/D and H/ACA box snoRNAs. (C) Fisher's exact test; (***) P < 4 × 10−28 and (***) P < 3 × 10−25, respectively, for C/D and H/ACA box snoRNAs, and (**) P < 0.01. (D) Fisher's exact test; (***) P < 2 × 10−27 and (***) P < 6 × 10−22, respectively, for C/D and H/ACA box snoRNAs, and (**) P < 0.01.