Expression of the dbl proto-oncogene in Ewing's sarcomas.

We have investigated the expression of the dbl proto-oncogene in childhood tumors of known or suspected neuroectodermal origin. We found that while the dbl gene is consistently found expressed in Ewing's sarcoma as a single mRNA species, of approximately 5.0 kb, it is generally absent in two seemingly related categories of tumors, neuroblastoma and neuroepithelioma. The specificity of expression of the dbl proto-oncogene in Ewing's sarcoma supports the concept that Ewing's sarcoma may be differentiated from two closely related tumors, neuroblastoma and neuroepithelioma, on the basis of the presence of specific molecular markers.