Researchers [discovered](https://www.sciencedaily.com/releases/2026/05/260515233329.htm) an unexpected property of one of the most dangerous oncogenic proteins — MYC. It turned out that it not only accelerates the growth of cancer tumors but also physically repairs their DNA after chemotherapy. This finding explains why some types of cancer are extremely resistant to aggressive treatment. The article about the discovery was [published](https://genesdev.cshlp.org/content/early/2026/05/14/gad.352832.125) in the journal Genes. For decades, it was believed that the role of MYC was solely to activate genes that cause cells to grow uncontrollably. However, chemotherapy and radiation work by causing total DNA damage to the tumor. Cancer cells should die, but many of them successfully cope with this medical stress. The research team found that a modified form of the MYC protein can move directly to the sites of critical DNA breaks. There, it acts as a repair supervisor, quickly gathering other proteins around it for the emergency restoration of the genetic code, saving the cancer cell from death. Tumors with high MYC activity recover phenomenally quickly, nullifying all efforts of doctors and making standard chemotherapy practically useless. This discovery may help scientists better understand the reasons for the resistance of some types of cancer to treatment and create more effective therapeutic methods, reports bb.lv. This could be particularly important in the fight against aggressive tumors, such as pancreatic cancer, where standard chemotherapy often proves to be ineffective.