The p53 gene has been extensively studied in recent years, with initial results considering it a tumor promoter. However, currently it is not only recognized for being a tumor repressor, but also for playing a leading role in other cellular processes such as maintaining the integrity of the genome, apoptosis, senescence and development, among others. The limits of its scope are still unknown; however, the information obtained has transcended clinical applications and there is probably much more to explore and implement regarding this multifaceted guardian.