PTEN and neoplasm: These include transcriptional activation by Ras (Johnson et al., 2000) and MYC (Gomez-Roman et al., 2003), as well as loss of tRNA gene repression by the RB (White et al., 1996), p53 (Cairns and White, 1998), PTEN (Woiwode et al., 2008) and BRCA1 (Veras et al., 2009) tumour suppressors.