AFF3 and prostate cancer: In addition, four FGFR fusion-positive patients were identified in the MI-ONCOSEQ study, with FGFR2-BICC1 rearrangements occurring in two cases of cholangiocarcinoma, a FGFR2-AFF3 fusion occurring in breast cancer, and a SLC45A3-FGFR2 fusion occurring in prostate cancer.