Have we mentioned the ifs? Like all potentially disruptive innovations, gene sequencers could fizzle. Their success depends on unpredictable events: how fast the technology improves, how quickly researchers can make medical discoveries based on the new machines and–most critically–whether drugs can be developed to treat diseases. Gene test prices could drop, becoming a low-margin commodity like medical blood tests (cholesterol, blood sugar and so on), which, at a few bucks a pop, are a $40 billion business. Ultimately Rothberg’s machine may not win. Like the Commodore 64 home computer that dominated in the 1980s and disappeared soon after, the PGM could be quickly eclipsed.