Question

1)Why are tumor suppressor genes are hard to identify?
2) Why is the p53 gene the guardian gene?

please explain your answer
thanks

Answer 1

Tumor suppressor genes are normal genes that slow down cell division, repair DNA mistakes, or tell cells when to die (a process known as apoptosis or programmed cell death). When tumor suppressor genes don't work properly, cells can grow out of control, which can lead to cancer

Tumor Suppressor Genes Are hard to Identify Because A typical cancer depends on a whole set of mutations—usually a somewhat different set in each individual patient—and introduction of any single one of these into a normal cell is usually not enough to make it cancerous. This genetic cooperation makes it hard to test the significance of mutations on which suspicion falls. To make matters worse, most cancer cells will contain mutations that are accidental by-products of genetic instability, and it can be difficult to distinguish these from the mutations that have a causative role in the disease.

Despite these difficulties, many genes that are repeatedly altered in human cancer have been identified—more than 100 of them—although it is clear that many more remain to be discovered. We will call such genes, for want of a better term, cancer-critical genes, meaning all genes whose mutation contributes to the causation of cancer

2. p53, also known as TP53 is a gene that codes for a protein that regulates the cell cycle and hence functions as a tumor suppression. It is very important for cells in multicellular organisms to suppress cancer.

The TP53 gene provides instructions for making a protein called tumor protein p53 (or p53). ... If the DNA cannot be repaired, this protein prevents the cell from dividing and signals it to undergo apoptosis. By stopping cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors

, p53 has been described as "the guardian of the genome" because of its role in conserving stability by preventing genome mutation.