Ranking of nine candidate reference genes using geNorm and NormFinder softwares. (a-g) GeNorm ranks the candidate reference genes based on their stability parameter M. The lower the M value, the higher the expression stability. (h-n) NormFinder ranks the genes based on a calculated stability value. The lower the stability value, the higher the expression stability. All: when all types of stimulated + control + no-culture were considered together. Irrespective to stimulation: when all the stimulated and non-stimulated control groups were considered together; Control: no stimulation; NC (no culture): PBMCs did not culture, just after isolation from blood, it was used for RNA isolation in order to perform mRNA expression study. LPS: lipopolysaccharide; LTA: lipoteichoic acid; LPS + LTA (combined): lipopolysaccharide used together with lipoteichoic acid.