Promising research is moving ahead for new medicines that spark a patient's own immune system to fight their cancer. PD1 and PDL1 are being studied in solid tumors. But CLL expert Dr. John Gribben from London thinks these drugs may do even better in CLL. He explains how they could work and his hope that drug companies developing these drugs will turn their attention to advancing them for CLL. It's another chapter in the story of the promise of refined immunotherapy for CLL.