The gene encodes for the enzyme syn-stemod-13(17)-ene synthase that catalyzes the conversion of syn-copalyl diphosphate into syn-stemod-13(17)-ene an intermediate in the diterpene phytoalexin metabolism. It is a class I diterpene synthase and is a member of the kaurene synthase family. The same enzymatic reaction also produces about 3% of the stemar-13-ene a byproduct of the reaction catalyzed by the rice gene KS8 (GR:0101307) with which KS11 bears a very high homology. The KS11 reaction products include 92% exo-stemodene and 5% endo-stemodene. Authors Morrone et al (2006) report that this is a novel gene and the assembled rice genome lacks the sequenced region where it may map.