Additionally, among the 5 cases of breast DFSP with genetic information, 4 cases presented the collagen type I α 1 (COL1A1)-platelet-derived growth factor (PDGF) β fusion gene, which often accompanies a chromosomal translocation involving 17q22 (COL1A1 at 17q22) and 22q13 (PDGFβ at 22q13) and a ring chromosome formation; the protein product of COL1A1-PDGFβ fusion gene binds to the PDGF receptor and further stimulates the growth of DFSP cells by autocrine secretion [21]. The gene discussed is PDGFB; the disease is dermatofibrosarcoma protuberans.