Learn more about cell phones and the current research into whether they could cause brain tumors, “Sanjay Gupta, M.D.,” Saturday, 7:30 a.m. and 2:30 p.m. ET and Sunday at 7:30 a.m. ET. By Dr. Sanjay Gupta, Chief Medical Correspondent Just about every time I use a cell phone, I plug in my wired earpiece first. [...]