An immune-system-supressing drug that was isolated from a mold in the mid-1970s by the Swiss firm F. Hoffmann-LaRoche & Co. AG. The drug is used to prevent (organ recipient’s) immune system from “rejecting” a transplanted organ and typically must be taken by the organ recipient for the duration of his/her lifetime. Cyclosporin’s mechanism of action is to prevent the divalent calcium cation (Ca²†) from entering T lymphocytes to activate certain genes within those T lymphocytes (that trigger the “rejection” process). In 1996, Thomas Eisner reported that the mold Tolypocladium inflatum, from which cyclosporin is harvested, prefers a natural (wild) substrate of a deceased dung beetle.