CXCL12 and alveolar rhabdomyosarcoma: When the expression of RasGRF1 was down-regulated in ARMS cells by an shRNA strategy, these RasGRF1-kd RMS cells did not respond to stimulation by SDF-1, HGF/SF, Igf-2 or insulin by phosphorylation of p42/44 MAPK and AKT and lost their chemotactic responsiveness; however, their adhesion was not affected.