Mazumder et al. have reviewed the regulatory roles of under-reported SIRTs (mainly SIRT2, SIRT4, and SIRT5, which lack direct reported associations with LF) in basic cellular and mitochondrial metabolic pathways critical to LF.607 Overall, they have suggested that SIRTs appear to exert a protective action in LF, except SIRT2, which might have a pro-fibrotic action given its proinflammatory effects observed in asthma.607 In summary, studies on the function of SIRTs in regulating LF have potential. This evidence concerns the gene SIRT2 and asthma.