SAN FRANCISCO -- The University of California, San Francisco has more than doubled the size of its cancer research facilities with the opening of a new center.

The university says the five-story Helen Diller Family Cancer Research Building that opened Tuesday will allow more cancer researchers to collaborate under one roof. The 160,000-square-foot building will house more than 400 scientists.

Achievements in cancer research at UCSF include the discovery of cancer's genetic roots. The university's current chancellor, Dr. J. Michael Bishop, received a Nobel Prize for the breakthrough along with fellow researcher Dr. Harold Varmus.

The center was funded in part by a $35 million donation from San Francisco philanthropist Helen Diller and $20 million from the Atlantic Philanthropies.