Left panel: Representative Western blots illustrating the expression of SMC6, SMC5 and FANCD2 in protein extracts from HeLa cells 48 hours after transfection with the indicated siRNAs. Right panel: Relative expression of SMC5, SMC6 and FANCD2. We performed individual experiments for each cell line with technical replicates. In each individual experiment, we first normalized SMC5, SMC6 or FANCD2 expression to that of Vinculin (internal control) and calculated its relative level in each cell line in relation to the target protein/Vinculin ratio of the siLacZ transfected cells, which was set as one in each experiment. Data present the mean+/-S.E.M. and were analyzed by unpaired t-test. SMC5 in siSMC6: n=7 and p=0.0002; SMC5 in siFANCD2: n=7 and p=0.0016; SMC6 in siSMC5: n=8 and p<0.0001; SMC6 in siFANCD2: n=24 and p<0.0001; FANCD2 in siSMC6: n=30 and p<0.0001; FANCD2 in siSMC5: n=10 and p=0.0008. 