PDGFB and dermatofibrosarcoma protuberans: For example, congenital FSA often bears ETV6-NTRK3 gene fusions that activate the Ras-MAP kinase and PI3 kinase signaling cascades12. The majority of adult human low-grade fibromyxoid sarcomas have FUS-CREB3L2 or FUS-CREB3L1 fusions, with the highly aggressive sclerosing epithelioid fibrosarcomas prevalently bearing EWSR1-CREB3L1 fusions13. In addition, greater than 90% of Dermatofibrosarcoma Protuberans (DP) tumors carry COL1A1-PDGFB fusions leading to both improved diagnosis and neoadjuvant therapy with PDGFR inhibitors for patients with recurrent, nonresectable, or metastatic disease14.