DDR2 and liposarcoma: DDR2 is a receptor tyrosine kinase that is activated by fibrillar collagens and might promote metabolism in adipocyte cells.[20] Gene amplification and overexpression of DDR2 has been reported in liposarcoma,[21,22] and a variety of solid tumors.[23,24] To our knowledge, ours is the first report to show DDR2 overexpression in an IMT.