Harvard Medical School professor Timothy Springer's $5 million investment in biotech firm Moderna in 2010 has turned into $400 million in value at the company's recent IPO. Springer is the fourth-largest shareholder of Moderna, which hopes to make personalised cancer vaccines. In 1999, the 70-year-old had made about $100 million when he sold his first venture, a drugmaker called LeukoSite.