Supporting our model, gene expression profiles of the refractory chemoresistant rhabdomyosarcoma PDXs strikingly corresponds with the stemness-associated gene expression signature identified in our study, including significant upregulation of ALDH6A1, SOX4, CDH15, and MYOD1 expression as well as downregulation of ALDH1A1 and ALDH1A3 (Figure 7). Here, MYOD1 is linked to rhabdomyosarcoma.