RECQL4 and Rothmund-Thomson syndrome: The possible involvement of RECQL4 in the repair of DNA double-strand breaks (DSB) has been demonstrated by the coincidence of RECQL4 nuclear foci with the foci formed by RAD51, a crucial protein which functions in homologous recombination of DNA DSB [69], as well as by the sensitivity of fibroblasts from RTS patients to ionizing radiation [6] and by the participation of RECQL4 in DSB repair in Xenopus egg extracts [70].