For example, studies in mouse strains expressing mutant p53 corresponding to R175H and R273H hot spot mutations in human cancers revealed that these mutants exhibited gain-of-function properties in addition to loss of normal p53 function (i.e. altered tumour spectrum in addition to more metastatic tumours) (Freed-Pastor and Prives, 2012, Lang et al., 2004, Olive et al., 2004). This evidence concerns the gene TP53 and neoplasm.