As had previously been shown with "heart, stroke and bone marrow cancer research," a review by medical researchers found that "breast cancer studies funded by drug companies are more likely to yield positive findings than those without pharmaceutical industry [3] backing." Researchers at the University of North Carolina "looked at 140 studies published in 2003, 1998 and 1993 in 10 medical journals on breast cancer therapies, nearly half of which were deemed to have had drug company involvement in the form of funding, provision of drugs or participation of a company scientist." The lead author of the review said it is possible that industry-funded studies "are biased and negative studies are not being published," but it could also be true that industry-funded research focuses on "safer bets," or drugs more likely to do well.