 Researchers in Japan have genetically manipulated roses by using RNA interference to knock out endogenous DFR, adding a gene DFR from an iris, and adding a gene for the blue pigment, delphinidin, in an effort to create a blue rose, which is being sold worldwide.Dihydroflavonol 4-reductase is an enzyme part of the lignin biosynthesis pathway.In "Arabidopsis thaliana", the enzyme uses sinapaldehyde or coniferyl aldehyde or coumaraldehyde and NADPH to produce sinapyl alcohol or coniferyl alcohol or coumaryl alcohol respectively and NADP+.