dr. potti's research. they emailed their questions to duke, and dr. ical errors, but he said that new work confirmed his results. duke moved ahead. drs. nevins and potti applied for patents and started a company to market the process. they and duke stood to make a fortune. patients enrolled in the clinical trial so that their tumors could be surgically biopsied to be matched with the best drug. but at m.d. anderson, during months of analysis, baggerly and coombes kept finding errors that they thought were alarming. >> baggerly: one of the things that was especially disturbing was that these types of errors happened again and again and again. that was far beyond anything that we'd seen. >> pelley: they suspected dr. potti had somehow reversed some of the data, and that some of the patients could be getting not the best drug for their tumor, but the worst. >> coombes: then, you would be giving patients drugs that would definitely not benefit them. so there's clear potential for harm there. >> pelley: exactly the opposite of what this was supposed to be.