 TEL-TRKC is a fusion gene generated by chromosomal translocation and encodes an activated tyrosine kinase.     ///    "We expressed the two TEL-TRKC variants in vivo by using the 3' regulatory element of SCL that is selectively active in a subset of mesodermal cell lineages, including endothelial and hematopoietic stem cells and progenitors. "    ///    The leukemia form of TEL-TRKC (-exon 5 of TEL) enhanced hematopoietic stem cell renewal and initiated leukemia.     ///    "In contrast, the TEL-TRKC solid tumor variant (+ TEL exon 5) elicited an embryonic lethal phenotype with impairment of both angiogenesis and hematopoiesis indicative of an effect at the level of the hemangioblasts. "    ///    "The ability of TEL-TRKC to repress expression of Flk1, a critical regulator of early endothelial and hematopoietic cells, depended on TEL exon 5. "    ///    "However, a single exon difference (in TEL) in TEL-TRKC fusions is associated with the two sets of cancer phenotypes. "