BRG1-BRD increases the sensitivity of cancer cells to radiotherapy by disrupting the γ-H2AX and 53BP1 pathways, leading to reduced DNA repair efficiency, G2-M checkpoint defects, and increased apoptosis.442 Additionally, acetylation of the chromatin remodeling protein MORC family CW-type zinc finger 2 (MORC2) can activate the G2 checkpoint and induce DNA damage, thereby improving the radiosensitivity of breast cancer cells443 (Fig. 4). The gene discussed is TP53BP1; the disease is cancer.