"tolypocladium inflatum", the species currently used for mass production of cyclosporin, has the biosynthetic genes arranged into a 12-gene cluster. of these 12 genes, sima () is the cyclosporin synthetase, simb () is the alanine racemase, and simg (similar to ) is the polyketide synthase. these genes are associated with an active retrotransposon. although these sequences are poorly-annotated on genbank and other databases, 90% similar sequences can be found for the cyclosporin-producing "beauveria felina" (or "amphichorda ~"). simb has two paralogs in the same organism with different but overlapping functions thanks to their low speficity.