Cincinnati Children's Hospital Medical Center Oct 29 2025 Immune checkpoint inhibitors (ICIs) emerged in the US about 15 years ago as an exciting class of cancer treatments that have achieved complete and durable remissions for thousands of people with end-stage metastatic cancers. However, many other patients have tumors that remain "cold" and unresponsive to these treatments. Now, scientists at Cincinnati Children's have discovered a specific gene mutation lurking behind this lack of response-