American biotechnology firm. Founded in 1979, Horizon Corporation currently employs over 3500 employees worldwide. The company holds more than 4000 patents with another 2000 pending. The company is headquartered in downtown San Francisco and is traded on both the New York Stock Exchange and the Pacific Exchange under the symbol HOR.

Horizon manufactures nine products, including the anti-cancer drug Proacteron and the Hemezyme line of synthetic human antibodies. The company is an active participant in the Human Genome Project and the Rainforest 2000 initiative. Current research fucuses on exploiting the biodiversity of the South American rainforest and developing genetically engineered strains of crops and livestock for the third world. Over the years Horizon has become known for its corporate generosity, donating sizable sums to programs to help the homeless, as well as numerous environmental causes.