The softwares GeNorm , NormFinder  and BestKeeper  were used according to the instructions supplied. This required that raw Ct values were transformed to different input formats for GeNorm and NormFinder analyses. For analysis using BestKeeper software, raw Ct values were inputted. For the statistical comparison of two groups, an unpaired, two-tailed t test was used in GraphPad Prism 7 software (GraphPad). P values indicated in the figure legends.