Toxicity in humans has not been reported, though mass die-offs of geese are known. Consumption of "E. crepidifolium" by geese leads to muscle paralysis from which the animals eventually die (hence the German common name "Gänsesterbe“, or geese death, for this species). Rabbits are also considered susceptible, but chickens are reportedly resistant to "E. crepidifolium" toxicity. Due to its close phylogenetic relationship with the well-studied model plant species "Arabidopsis thaliana, E. crepidifolium" has been proposed as a suitable system for investigating the cardenolide biosynthetic pathway. Progesterone 5-beta-reductase, which was initially proposed as an enzyme of cardenolide biosynthesis in "Digitalis," also has been cloned from "E. crepidifolium." However, the natural substrate of this "E. crepidifolium" enzyme has not yet been identified. 3-beta-hydroxysteroid dehydrogenases represent another enzyme class that is predicted to be involved in cardenolide biosynthesis. Comparison to "A. thaliana" genes identified three predicted 3-beta-hydroxysteroid dehydrogenases in "E. crepidifolium" ("EcHSD1," "EcHSD2", and "EcHSD3"). "In vitro" assays showed that all three enzymes catalyze the dehydrogenation of pregnenolone and the 3-reduction of 5-alpha/beta-pregnane-3,20-dione. Whereas "EcHSD1" expression was not induced by tested stress conditions, "EcHSD2" expression was upregulated by osmotic stress, and "EcHSD3" expression was upregulated by both osmotic stress and treatment with methyl jasmonate, an endogenous elicitor of chemical defenses in many plant species.