When oncologist Dr. Luis Diaz Jr. started focusing on mutations found in tumors, he stumbled onto something incredible. Diaz made an amazing breakthrough in the late 2000's when he realized immunotherapy treatments were shrinking tumors in lung cancer. The key was understanding that lung cancer is a cancer with a lot of mutations. These genetic alterations, called "mismatch repair" (MMR), were no match for immunotherapy treatments, with activated immune cells attacking the cancer cells. Fast forward to a clinical trial in 2022, and Diaz, and his Memorial Sloan Kettering colleague Andrea Cercek, led a cancer trial with shocking results. Patients diagnosed with advance rectal cancer had a 100% success rate! The first generation Peruvian American doctor is excited for what the future holds. He envisions running similar trials for prostate, gastric, esophageal, and pancreatic cancer. Diaz is also excited about the possibility of transforming cancer treatment in the developing world, where radiation, chemotherapy or surgery isn't an option.