Paul Mischel explains how ecDNA drives cancer treatment resistance and enters clinical testing

Stanford physician-scientist Paul Mischel, motivated by his father's death from stomach cancer, describes how oncogenes can jump from chromosomes onto circular extrachromosomal DNA (ecDNA), breaking conventional rules of genetic inheritance. ecDNA lets cancer cells remodel their genomes rapidly enough to resist therapies, including precision oncology and immunotherapy. The first drugs targeting ecDNA are already being tested in clinical trials, moving the work from concept toward clinical translation.