The orphan snoRNA ACA11 is overexpressed co‐transcriptionally with the NSD2 gene in MM patients as a result of the t(4;14) chromosomal translocation, and stimulates cell proliferation.7, 8 Here, we demonstrated for the first time that ACA11 also up regulates ribosome biogenesis in a ROS‐dependent manner. This evidence concerns the gene SCARNA22 and Miyoshi myopathy.