RecG expression reduces SCE in a French-Canadian BLM- line. 3A: Normalized sister chromatid exchange frequencies. “BLM- FC”: EBV-immortalized lymphocytes homozygous for an inactivating (S595X) mutation. “BLM- FC: RecG fuse”: the same cells expressing low levels of the RecG-EGFP fusion protein. 3B: Western blot showing relative protein levels. Blue oval: RecG-EGFP fusion protein. “BLM- FC: RecG fuse”: protein extract from French-Canadian BLM- cells stably expressing low levels of the RecG-EGFP fusion protein. “BLM- FC”: protein from French-Canadian BLM- cells lacking a RecG transgene. See also Table1 for EGFP quantitation by flow cytometry.