It's a question that has nagged users of cellphones for a long time: are they safe to use. The short answer -- yes, but the questions continue.
For example, two government studies that bombarded rats and mice with cellphone radiation -- found a weak link to some heart tumors.
The rat research, released last week, shows a small increase in an unusual type of heart tumor in male rats.
But the results didn't hold up in tests of female rats or in tests involving mice.
The lead author of the research says he isn't changing his cellphone use or asking his family to -- and says he and other researchers haven't cut back on their use of cellphones.