This substance shows promise for cancer therapy; it is about to begin clinical trials with patients suffering from brain or breast cancers. Squalamine was discovered in 1993 in the stomach and liver of the dogfish, a type of shark. Its name is a compound of amine with squalus, the name of the dogfish genus, which derives from the Latin squalum for a type of fish. The compound is believed to act by preventing blood vessels in the human body from obeying commands from cancer cells to link to them, so starving them of the blood supply that is essential for growth. One of the main hopes for this new drug is that cancers will fail to develop resistance to it because it doesn’t act on the cancer cells themselves, but on the existing blood vessels. Several related types of compound have been discovered recently, including magainins from the African clawed frog, all of which are members of a class of substances called peptidomimetics which mimic the action of peptides in the body to block abnormal or unwanted growth. Many of them, including squalamine, also seem to have antibacterial or antiviral action and a couple have shown promise as treatments for AIDS.