Degree of correlation between normalization strategies in more heterogeneous datasets. Scatter plot of ratio values obtained from sample set "K" for genes which together illustrated a wide range of responses (from strong over-expression to repression, see Figure 8 for some of them). X axis: ratios calculated using the three most stable genes (NF(UBC 6, TFC 1, KRE 11)); Y axis: ratios calculated using NF(TAF 10, FRP 2, ALG 9)(A) and NF(ACT 1)(B). Dotted line: y = x. The equation and correlation coefficient of the linear regression fit (not reported) were y = 1.030x, R2 = 0.916 (A) and y = 2.405x, R2 = 0.124 (B).