The p53 gene is responsible for sending proteins to damaged cells and either repairing them or causing damaged cells to die. The process of cell death is called apoptosis. When the gene is not working due to a mutation, these proteins that repair cells or eliminate damaged cells are not sent, and abnormal cells are allowed to divide and grow into cancer.
A very simplistic way to look at the function of the p53 gene would be to picture yourself as the main plumbing valve (p53 valve) monitoring the water flow to a giant building with a complex plumbing system. If you detect a water leak somewhere in one of your pipes and your valve is "functioning properly," you would be able to make a phone call to a plumber. The plumber or p21 protein could then come to your building and either repair the pipe or remove it completely to stop the water leak. If you were unable to make the call because your p53 valve is damaged or mutated, the plumber would not be called and the leak would continue (cancer cells would continue to divide) and eventually flood your home.
Li-Fraumeni is an extremely rare mutation of the p53 gene located in our DNA and stops damaged cells from dividing. The risk of developing malignant tumors in young adulthood is 98% in females, 75% males. Once cancer is identified, the cancer cells are extremely resistant to typical cancer treatments (Chemo & Radiation) because of the original gene mutation. This syndrome is truly a double edged sword.
p53 mutations are present in 50% of all cancer cells. These mutations are deadly and can lead to untreatable cancers. Fully understanding the mutated p53 gene and finding a way to repair it is vital in saving any cancer patient.