SNORA13 and osteosarcoma: This trend was not cell line-specific: indeed SNORD3A, SNORA13 and SNORA28 and their respective host genes were progressively up-regulated also in the Dox-resistant variants Saos-2/DX30, Saos-2/DX100 and Saos-2/DX580 (Figure S2A,B) derived from Dox-sensitive Saos-2 cells, a second human osteosarcoma cell line [33].