Welcome to Fortune’s 2015 40 Under 40, our annual ranking of the most influential young people in business—for the first time, 100 percent brand new. Read on to meet these disruptors, innovators, rebels (and, yes, unicorns)—and prepare to be inspired. ...

... #38: Ashifi Gogo, 34

Co-founder and CEO, Sproxil

Ashifi Gogo Th'10 & Dartmouth's first PhD Innovation Program graduate.

Born and raised in Ghana, Gogo – a Dartmouth engineering PhD – co-founded Sproxil in 2009 to fight the scourge of counterfeit pharmaceuticals in Africa. His authentication technology – which relies on basic mobile phones and text messaging – has since been used to verify the source of more than 19 million products. And it’s now being deployed by a number of big brands (think Novartis and Cipla) in six countries – from Nigeria to Pakistan – to find fakes of all kinds: drugs, but also auto parts, underwear and health and beauty products. America’s highest office holders are among Gogo’s fans: Bill Clinton called his company "a remarkable achievement"; in 2013, the Obama administration recognized him as an "Immigrant Innovator" and a "Champion of Change."