Knock-down of PAX3-FKHR in several ARMS cell lines also caused G1 arrest, with concomitant decrease in the fraction of S phase cells, while ectopic expression of PAX3-FKHR in fibroblasts was found to accelerate the G0/G1 to S cell cycle transition 17–20. Here, PAX3 is linked to alveolar rhabdomyosarcoma.