Aaron Loeb’s latest play, “R.O.I. (Return on Investment), opening this week in a San Francisco Playhouse premiere, may call to mind the Theranos debacle. It is a funny, unnerving and only slightly futuristic tale about a wily scientist who says she can eradicate cancer, and the two eager venture capitalists who trust her— until they don’t. Loeb at first was inspired by the Silicon Valley true […]