PAX3 and neoplasm: To investigate the transcriptional basis of this Pax3:Foxo1a dynamic expression, we performed QPCR of Pax3 and Foxo1 using cell cycle specific sorted C2C12 mouse myoblast cells of the genotype Pax3(wt/wt) and mouse aRMS primary tumor cells of the genotype Pax3(wt/Pax3:Foxo1a).