Equivalence test for candidate reference genes. Each line indicates the difference in logarithmic (base 2) expression level between tumour and normal tissues, with the upper and lower bars representing the upper and lower limits of symmetrical confidence intervals respectively. All genes were equivalently expressed with confidence intervals within fold change of 2 (deviation area 1, -1).
Chang et al. BMC Cancer 2010 10:173 doi:10.1186/1471-2407-10-173