Total RNAs of Vehicle- or S100A8/A9-treated BMDCs were extracted using TRIzol® Reagent according the manufacturer's instructions (Invitrogen). Total RNA was treated with RNase-free DNase I for 30 min according to the manufacturer's protocols. The poly(A)-containing mRNA was purified using Oligo(dT) beads from the total RNA and then fragmented into 100- 200 nt using divalent cations at elevated temperature. The fragmented mRNA was reverse transcribed with SuperScript II and further extended into double-stranded cDNA using RNaseH and DNA Pol I by random priming. The cDNA was subsequently adapter-ligated with unique indices and amplified following PCR. The libraries were analyzed by Agilent Bioanalyzer 4200 and quantified by qPCR before being sequenced on the Illumina sequencing platform.