There are 50 hospitals on 5 continents that use Watson for Oncology, an IBM product that charges doctors to ingest their cancer patients' records and then make treatment recommendations and suggest journal articles for further reading.

The doctors who use the service assume that it's a data-driven AI that's using data from participating hospitals to create massive data-sets of cancer treatments and outcomes and refine its inferences. That's how IBM advertises it. But that's not how it works.