TP53 and breast cancer: While non-missense mutations will end up producing no p53 protein, missense mutations form a mutant protein that has loss of function (LOF) of p53’s transcription factor and tumour suppressive activity which occurs in ~ 80% of p53 mutations in breast cancer.146 These LOF mutations drive cell proliferation and survival and thus metastasis147 and have been correlated with chemoresistance and lower efficacy of anti-tumour agents.148,149 Out of the 190 codons, 10 locations make up 30% of all missense mutations and are known as the “hotspot” mutations.