Ralph M. Steinman, an immunologist at Rockefeller University, has been named the recipient of the 2007 Albert Lasker Award for basic medical research in recognition of his discovery of dendritic cells, an important component of the body’s immune system. In announcing the prize, the Albert and Mary Lasker Foundation said Dr. Steinman’s pioneering research had “revolutionized our understanding of the events that instigate an immune response and unlocked the entire field of T-cell activation.”

Another American academic, Albert Starr of the Oregon Health and Science University, is among three other winners of Lasker awards announced on Saturday. Dr. Starr and a French surgeon, Alain Carpentier of the Georges Pompidou hospital in Paris, will share the award for clinical medical research in recognition of their development of bioprosthetic heart valves, opening up the field of valve-transplant surgery. Their discoveries have “prolonged and enhanced the lives of millions of people with heart disease,” the award citation says.

The fourth winner is Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, who will receive the award for public service in support of medical research. Dr. Fauci is being recognized as the principal architect of two government programs, one dealing with AIDS and the other with biodefense. The award citation praises him as “a world-class investigator” who “has spoken eloquently on behalf of medical science to the public, Congress, and successive administrations.”

The Lasker Awards are considered the nation’s most prestigious medical prizes and are often regarded as steppingstones to Nobel Prizes, because more than 70 Lasker honorees have gone on to become Nobel laureates. This year’s prizes, which are worth $150,000 each, will be presented on September 28 at a ceremony in New York. —Charles Huckabee