The article reviews the recent progress in understanding the functions of mutant p53 proteins in cancer and discusses therapeutic strategies targeting these proteins. Mutant p53, which arises from various *TP53* mutations, has both lost wild-type p53 tumor suppressor activity and gained functions that contribute to malignant progression. These functions include gain-of-function (GOF) activities, such as promoting invasion, motility, and metastasis, as well as novel roles in cell reprogramming, expansion, and interaction with the tumor stroma. The article highlights the complexity of mutant p53, with different mutations leading to distinct phenotypes and mechanisms. Therapeutic strategies are explored, including restoring wild-type p53 function, promoting mutant p53 degradation, targeting downstream pathways, and exploiting synthetic lethality. The authors emphasize the need for a deeper understanding of mutant p53 functions and the development of efficient targeting mechanisms to translate research into clinical practice.The article reviews the recent progress in understanding the functions of mutant p53 proteins in cancer and discusses therapeutic strategies targeting these proteins. Mutant p53, which arises from various *TP53* mutations, has both lost wild-type p53 tumor suppressor activity and gained functions that contribute to malignant progression. These functions include gain-of-function (GOF) activities, such as promoting invasion, motility, and metastasis, as well as novel roles in cell reprogramming, expansion, and interaction with the tumor stroma. The article highlights the complexity of mutant p53, with different mutations leading to distinct phenotypes and mechanisms. Therapeutic strategies are explored, including restoring wild-type p53 function, promoting mutant p53 degradation, targeting downstream pathways, and exploiting synthetic lethality. The authors emphasize the need for a deeper understanding of mutant p53 functions and the development of efficient targeting mechanisms to translate research into clinical practice.