PHF6 and Borjeson-Forssman-Lehmann syndrome: Mutations in PHF6 are associated with Borjeson-Forssman-Lehmann syndrome and are also implicated in the development of cancer (Van Vlierberghe et al. 2010; Lower et al. 2002), supporting the notion that deregulation of rDNA transcription and rDNA R-loop resolution can result in disease.