Ranking results of most stable normalization genes. (A) The BestKeeper results for candidate genes. BestKeeper correlation coefficient is ploted on the y-axis. A higher correlation coefficient corresponds to a more stably expressed gene. (B) The geNorm results for candidate genes. The M-value (y-axis) calculated by geNorm is a measure of stability of the gene expression across specimens. Genes with lower M-values show increased stability. (C) The NormFinder results for candidate genes. NormFinder stability values are plotted on the y-axis, with lower stability values indicating a gene that is more stable.