To validate these findings, an independent experiment was performed, and the expression of the most and least stable reference genes, as identified by NormFinder software, was analysed by RT-qPCR. In agreement with the findings described above, there was no difference in Ct values observed for Hnrnpab, between the control and LPS treated samples, at 6 h (Fig. 2c). In the above-mentioned analysis, Gusb was identified as the most unstable reference gene under these particular experimental conditions, and was clearly regulated by LPS exposure at 6 h. In agreement with these findings, the Ct values observed for Gusb were significantly higher following LPS exposure at 6 h (p = 0.0304), indicating that LPS down-regulated Gusb gene expression levels. After 24 h exposure to LPS, Stx5a was identified as the most stably expressed gene between control and treated cells. This was validated in the independent experiment, with no difference seen in Ct values between the two treatments (Fig. 2d). In agreement with the above-mentioned analysis, Ct values observed for B2m were significantly lower in the LPS treated BMDMs, as compared to controls (p = 0.0034), indicating that LPS up-regulated B2m expression at this time point.