FGFR1OP, also known as FGFR1 oncogene partner, belongs to the FGFR1OP family. This protein is a largely hydrophilic protein postulated to be a leucine-rich protein family member. A t(6;8)(q27;p11) chromosomal translocation, fusing this gene and the fibroblast growth factor receptor 1 (FGFR1) gene, has been found in cases of myeloproliferative disorder.