CSF1 and dermatofibrosarcoma protuberans: Imatinib, a multi-target tyrosine-kinase inhibitor, and aside form GIST has been shown to have activity in several sarcoma subtypes where it interferes with key oncogenic drivers: the protein product of the COL1A1-PDGFB fusion transcript in dermatofibrosarcoma protuberans (DFSP) [15, 16] and the colony-stimulating factor 1 in pigmented vilonudular synovitis [17].