Scatter plots of Median Probeset Expression Values of Farmer et al. Data vs. Doane et al. Data. The blue symbols represent the data after quantile normalization (QN), the green symbols represent the data after subsequent cross-study normalization by XPN, and the yellow symbols represent the data after subsequent update of probeset definitions. The red line depicts the unity line, i.e. y = x. The legend lists Pearson correlation coefficient for each normalization step. All data has been natural-log transformed.
Sanga et al. BMC Medical Genomics 2009 2:59 doi:10.1186/1755-8794-2-59