Figure 3.

Expression stability of the 38 newly identified RGs evaluated by geNorm (A) and NormFinder (B). (A) Ranking of geNorm is based on the principle that logarithmically transformed gene expression ratio between two ideal internal control genes should be identical if both genes are stably expressed in the tested sample set. Expression stability values (M) of the 38 candidate RGs are shown, RGs with a higher M value are less stably expressed. (B) NormFinder is a model-based approach that evaluates expression variation by comparing the variation within and between a certain number of sample groups and RGs with lower combined levels of intra and intra-group variation were regarded to be more stably expressed.