While dibenzylbutyrolactone lignans (DBLs) produced from various plants are levorotatory, members of the Thymelaeaceae family, which includes many medicinal and ornamental plants, have been observed to produce dextrorotatory DBLs. Until now, the mechanism underlying the production of dextrorotatory DBLs has remained entirely unknown. In this issue, however, Tutihashi et al. demonstrate that the selectivity of the substrate enantiomers of the two enzymes involved in DBL production—pinoresinol/lariciresinol reductase and secoisolariciresinol dehydrogenase— determines the production of dextrorotatory and enantiomerically pure DBLs in Daphne genkwa (lilac daphne in English, fujimodoki in Japanese), a member of the Thymelaeaceae family.