Learn more about lung cancer at http://www.YouAndLungCancer.com Medical oncologists and lung cancer experts Dr. Joseph Leach and Dr. Naomi Fujioka provide an overview of immunotherapy and how it works for treating lung cancer. They also talk about immune checkpoints PD-L1 and CTLA-4. Currently, doctors test for the presence of PD-L1 in all lung cancers and this information is very important for treatment decisions.