Gene expression differences among the candidate reference genes. The log-transformed gene expression levels are represented by black circles. The intertissue variation is indicated by vertical bars that give a confidence interval for the difference. The two thin dashed lines represent the maximal standard deviation of the reference candidate genes, with a log expression levels difference between 0.5 and -0.5.
Barsalobres-Cavallari et al. BMC Molecular Biology 2009 10:1 doi:10.1186/1471-2199-10-1