Fig. 3. Regulation of double-strand break repair pathway choice. 53BP1: p53-binding protein 1; BRCA1: breast cancer type 1 susceptibility protein; CCDC98: coiled-coil domain-containing protein 98; HR: homologous recombination; MDC1: mediator of DNA damage checkpoint protein 1; NHEJ: non-homologous end-joining; pH2AX: phospho-histone H2AX; P: phosphorylated; PTIP: Pax transactivation domain-interacting protein; RAP80: receptor associated protein 80; RIF1: replication timing regulatory factor 1; RNF: RING finger protein; Ub: ubiquitin; UIM: ubiquitin-interacting motif.