The document discusses a proposed study to determine if excessive cell phone use causes glioma brain tumors and ipsilateral exposure in Puerto Rico. The study would examine the relationship between long-term cell phone use and risk of glioma tumors over 10 years. Participants would be surveyed about their cell phone use patterns and monitored for tumor development. The expected results are that heavy cell phone users would show an increased risk of both glioma tumors and ipsilateral exposure on the side of head used for calling.