Recognition of histone modifications by ‘reader’ proteins have a critical role in the regulation of gene expression. These days, histone lysine modifying acyl groups such as propionylation, butyrylation, crotonylation has been revealed. However, the function and the detailed mechanism by which histone modifications is unknown. The events responsible for reading the hyper-acetylated histone, which are necessary to initiate transcription of E2-regulated genes. These histone modifications are known to play important role in the localization of p300/CBP or BET protein. But how these novel histone modifications work is poorly understood. In this study, it is revealed that the co-activator TRIM24 regulates ERα target genes via novel histone modifications. So I will suggest the novel transcription-regulatory mechanism which includes novel histone modifications and TRIM24 in the breast cancer cell.