In many solid tumours, such as breast cancer [89], hepatocellular carcinoma [90], oesophageal cancer [91], and cutaneous squamous cell carcinomas [92], increased p300 expression is associated with an aggressive phenotype and a low survival rate; furthermore, histochemistry analysis of a variety of primary tumour tissues has revealed that lower overall levels of H3K18ac are associated with lower survival and a higher risk of recurrence in prostate cancer, renal cancer, lung cancer, pancreatic cancer and breast cancer [93,94,95,96,97]. This evidence concerns the gene EP300 and breast cancer.