Victor Ambros (born 1953, Hanover, New Hampshire) is an American developmental biologist who discovered the first known microRNA (miRNA). He is a professor at the University of Massachusetts Medical School in Worcester, Massachusetts.He received the Breakthrough Prize in Life Sciences in 2015 for his discovery of a new world of genetic regulation by microRNAs, a class of tiny RNA molecules that inhibit translation or destabilize complementary mRNA targets.