This beneficial effect was more pronounced in the combined Lp-PLA2 and YKL-40 RNAi group, supporting the idea that atherosclerosis is a complex, multifactorial process intertwined with inflammation [20,21] and that combined interference of Lp-PLA2 and YKL-40 reduces local inflammation more effectively than interference of Lp-PLA2 or YKL-40 alone; therefore, combined RNAi might play an antiatherogenic and anti-inflammatory role. This evidence concerns the gene CHI3L1 and atherosclerosis.