https://www.cnbc.com/2018/02/03/high-levels-of-cellphone-radiation-linked-to-tumors-in-male-rats-us-study.html

Male rats exposed to very high levels of the kind of radiation emitted by cellphones developed tumors in the tissues around their hearts, according to a draft report by U.S. government researchers on the potential health risks of the devices.

Female rats and mice exposed in the same way did not develop tumors, according to the preliminary report from the U.S. National Toxicology Program (NTP), a part of the National Institute of Environmental Health Sciences.