Using multiple loss-of-function alleles, we observed that mutations in the daf-7 gene, encoding a TGFβ family ligand, or in the daf-1 gene, encoding the Type I TGFβ receptor, abrogated the lifespan extension conferred by BD (Fig 1C and 1E; S2 Table). This evidence concerns the gene TGFB1 and Behcet disease.