The equivalent pathognomonic COL1A1-PDGFB gene fusion found in human dermatofibrosarcoma protuberans was found in a dermatofibrosarcoma protuberans-like canine tumor, with the equivalent fusion found being COL3A1-PDGFB in the dog (37). Here, COL3A1 is linked to dermatofibrosarcoma protuberans.