Our research group has previously studied the immunohistochemical expression of WT1 and cyclin D1 in the diagnosis of SRBCT on surgically-resected specimens, showing a diffuse and strong cytoplasmic staining for WT1 exclusively in RMS and a diffuse nuclear cyclin D1 expression restricted to EWS and NB [20,32]. This evidence concerns the gene EWSR1 and neuroblastoma.