BMDMs were treated with vehicle or LPS, for 6 h and 24 h, and then RNA was isolated using Trizol reagent (Life Technologies) and the Qiagen Rneasy Plus Mini Kit (Qiagen). The aqueous phase of the Trizol preparation was obtained, according to the manufacturer’s instructions, and was applied to the gDNA-eliminating column of the RNeasy Plus Mini Kit, and then RNA was isolated according to the instructions of the manufacturer (Qiagen). RNA was submitted to the Ramaciotti Centre for Genomics (UNSW, Australia) for gene expression microarray analyses using the Affymetrix Mouse Gene 2.1ST array. Array data were analysed using Partek Genomics Suite (Partek Inc. USA). Data files were grouped according to treatment (control or LPS) and individual gene lists for 6h and 24h LPS stimulation were generated by one way ANOVA comparison of the two groups, with a fold change cut off of −1.<fold change<1.4 (Additional file 1 Tables S2 and S3, respectively). Then, the two lists (6h and 24h) were combined, and a list of genes that were common to both lists was generated, and three candidate reference genes were then selected.