Scytonema varium is a cultured cyanobacterium of the genus Scytonema. It is one of many anti viral protein producing algae. In a similar manner to Cyanovirin-N from Nostoc and griffithsin from the red algae Griffithsia, Scytonema varium secretes the broad-spectrum antiviral protein scytovirin which can inactivate both the HIV virus,[ and Ebola virus,] offering hope of treatment for many diseases with viral etiology (cause). It is currently being investigated as a topical microbicide for HIV prophylaxis.