Replication-independent HRR is critical in order to eliminate chromosomal breaks before cell division occurs. This process operates in coordination with the S and G2 checkpoint machinery. HRR of replication-independent double-strand breaks (DSBs) requires the activation of ATM followed by ATM-mediated phosphorylation of DNA repair proteins. DNA repair and signaling proteins are then recruited to the DSBs. The ends of the DSBs must be resected which allows binding of RPA to the resulting ssDNA. Homologous DNA pairing and strand exchange then occurs followed by DNA repair synthesis and resolution of D-loop structures.