Note that Quest Diagnostics has a drugstore partnership with CVS[1], directly competing with Theranos+Wallgreens. Labcorp has similar offerings, although some are whitelabeled.
[1] http://ir.questdiagnostics.com/phoenix.zhtml?c=82068&p=irol-...
[1] http://ir.questdiagnostics.com/phoenix.zhtml?c=82068&p=irol-...