Fig. 1

Reproducibility of iTRAQ-based quantitative analysis of ubiquitylation in basal and luminal breast tumor xenografts. a iTRAQ reporter ion intensities of ubiquitylated peptides from the Basal 1 vs. Basal 2 xenografts. The inset shows an enlarged region of the plot for the ubiquitylated peptides with intensities <1.0e⁵. b iTRAQ reporter ion intensities of ubiquitylated peptides from the Luminal 1 vs. Luminal 2 xenografts. The inset shows an enlarged region of the plot for the ubiquitylated peptides with intensities <1.0e⁵. c Distribution of RSDs (%) of the iTRAQ reporter ion intensities of ubiquitylated peptides from Basal 1 vs. Basal 2 (black bars) and Luminal 1 vs. Luminal 2 (grey bars) xenografts