Left: An example of gene conservative clustering. Chromosome loci (50 kb) from different vertebrate genomes are 'pinned through' SIRT2 homologs. Arrows correspond to open reading frames: red-SIRT2 homologs, green-NF-kappaB inhibitor beta. Right: A proposed model of interactions between SIRT proteins and and NF-kappaB regulatory network. Dashed lines-putative links derived from the gene positional clustering.