Cyclopamine (11-deoxojervine) is a naturally occurring chemical that belongs in the family of steroidal alkaloids. It is a teratogen isolated from the corn lily (Veratrum californicum) that causes fatal birth defects. It prevents the embryonic brain from separating into two lobes (an extreme form of holoprosencephaly), which in turn causes the development of a single eye (cyclopia). The chemical was named after this effect, as it was originally noted by Idaho lamb farmers who contacted the US Department of Agriculture after their herds gave birth to cycloptic lambs in 1957. It then took more than a decade to identify the corn lily as the culprit. Later work suggested that different rain patterns caused the sheep to graze differently, impacting the amount of corn lily ingested by pregnant s