H2AX and laminopathy: XPC is themajor DNA damage recognition protein in NER [41] but did notexhibit nuclear foci in HGPS and RD cellsindicating that the colocalization of XPA and γ-H2AX was specific and notrelated to NER [19].Furthermore, in HGPS and RD cells treated with CPT (a DSB-inducer) XPA did notcolocalize to these CPT-induced DSBs though it still colocalized to theendogenous laminopathy-induced DSB foci.