<p>Protein levels were assessed by quantitative western blot analysis using specific antibodies against target proteins. Each bar represent the mean expression ratio of the target protein in the LR5 (resistant) cells relative to the reference value of 1 (dotted line) in the sensitive cells subsequent to normalization against either β-actin or tubulin (to avoid overlapping signals). Quantitative analysis enclosed an average of 3 to 5 biological replicates with standard deviations as indicated. The P values were calculated by one sample two tailed t test against a hypothetical expression ratio set to 1 (no change in expression). >90%, >95% and >98% confidence levels indicated by *, **, and ***, respectively. # Only non-ubiquitinylated FANCD2 was detected in the analyses.</p
