: the promiscuous king of mesenchymal neoplasia.

is the most commonly rearranged gene in mesenchymal neoplasia, and its myriad chimeric oncoproteins drive widely disparate neoplasms. Here, we survey selected rearrangements, including well-described fusions with CREB family members, and , as well as fusions in emerging entities such as mesenchymal neoplasms with and fusions. We also discuss recent data demonstrating the imperfect specificity of and, possibly, fusions.