Figure 2

Distribution of the expression levels of genes examined. Box plot representation of the expression levels of twenty candidate reference genes (solid line), two housekeeping genes (dashed line) and three target genes (dotted line) among the 120 biological samples. The expression level of each gene was represented as the absolute copy number per unit input total RNA (0.0625 μg), quantified by RT-qPCR using linearized plasmid standards. Primer design, assay efficiency and intra- and inter-assay variations were reported in supplementary data (Additional File 1).