The article discusses the mechanisms by which p53, a crucial tumor suppressor, functions to prevent cancer. p53 responds to various stress signals, including DNA damage, hyperproliferative signals, hypoxia, oxidative stress, ribonucleotide depletion, and nutrient starvation, by triggering transient cell cycle arrest, cellular senescence, and apoptosis. Recent studies have highlighted additional roles for p53 in regulating metabolism, stem cell maintenance, invasion, metastasis, and communication within the tumor microenvironment. The authors review the classical functions of p53 and emerging roles in tumor suppression, emphasizing the importance of p53 in maintaining genomic integrity, inducing cellular senescence, and promoting apoptosis. They also discuss the role of p53 in regulating cellular metabolism, inhibiting stem cell self-renewal, and imposing barriers to invasion and metastasis. The article concludes by highlighting the need for further research to understand the complex mechanisms of p53-mediated tumor suppression and the potential for therapeutic interventions targeting p53 pathways.The article discusses the mechanisms by which p53, a crucial tumor suppressor, functions to prevent cancer. p53 responds to various stress signals, including DNA damage, hyperproliferative signals, hypoxia, oxidative stress, ribonucleotide depletion, and nutrient starvation, by triggering transient cell cycle arrest, cellular senescence, and apoptosis. Recent studies have highlighted additional roles for p53 in regulating metabolism, stem cell maintenance, invasion, metastasis, and communication within the tumor microenvironment. The authors review the classical functions of p53 and emerging roles in tumor suppression, emphasizing the importance of p53 in maintaining genomic integrity, inducing cellular senescence, and promoting apoptosis. They also discuss the role of p53 in regulating cellular metabolism, inhibiting stem cell self-renewal, and imposing barriers to invasion and metastasis. The article concludes by highlighting the need for further research to understand the complex mechanisms of p53-mediated tumor suppression and the potential for therapeutic interventions targeting p53 pathways.