Sema4: Eli Casdin, Emily Leproust, Jason Ryan, Nat Turner

As part of its merger with special purpose acquisition company CM Life Sciences, Sema4 has appointed four new directors to its board: Eli Casdin, chief investment officer of Casdin Capital; Emily Leproust, CEO of Twist Bioscience; Jason Ryan, former chief operating officer and CFO of Magenta Therapeutics and former CFO of Foundation Medicine; and Nat Turner, cofounder of Flatiron Health.