Building on our knowledge that muscle development, regeneration, and stem cell self-renewal are regulated by the NOTCH1 pathway (Conboy et al., 2003; Kuang et al., 2008), we undertook experiments to assess a role for NOTCH1 in regulating human rhabdomyosarcoma growth through specifically affecting TPCs. This evidence concerns the gene NOTCH1 and rhabdomyosarcoma.