SNAI1, SNAI2, and SOX9 were also highly expressed in ERMS tumors and cell lines, compared to normal muscle; however, only SNAI1 mRNA and protein expression were reproducibly reduced following shRNA knockdown in both RD and SMS-CTR cells (Figures 4A, 4B, S4A, and S4B). This evidence concerns the gene SOX9 and embryonal rhabdomyosarcoma.