Real estate developer Stephen Grand and his wife Nancy pledged $50 million to the Weizmann Institute of Science for personalized medicine. The gift from the San Francisco residents — the largest single contribution ever made to the American committee of the Israeli medical research institute — will fund the Nancy and Stephen Grand Israel National Center for Personalized Medicine on the institute’s Rehovot, Israel, campus to study genomics, protein profiling, bioinformatics and drug discovery. Those…