The p53-binding protein 1 (53BP1) is a DNA damage response factor, which is recruited to nuclear structures at the site of DNA damage. DNA double-strand breaks (DSBs) are mutations that are detrimental to cell viability and genome stability, and must be repaired either through homologous recombination (HR) or non-homologous end joining (NHEJ). 53BP1 specifically promotes both NHEJ as well as the inhibition of HR repair, yet the decision making on a molecular level between these two routes not clearly understood.
