The researchers found that blocking the FSP1 protein caused a dramatic reduction in lung tumours in mice. When FSP1 was turned off, many cancer cells destroyed themselves, suggesting that this protein is crucial for tumor cell survival. In experiments with mice that lacked FSP1, smaller tumors formed and increased cancer cell death was observed. A similar effect was observed with the drug icFSP1, which inhibits this protein. FSP1 is more important in protecting cancer cells from self-destruction compared to another protein, GPX4. In lung cancer patients, higher levels of FSP1 were associated with worse disease outcome. The results point to FSP1 as a potential target for new treatments for stubborn forms of lung cancer.