RPS6 and acute lymphoblastic leukemia: Interestingly, the RPS6‐haploinsufficient case exhibited rRNA maturation defects similar to those seen previously in shRNA‐targeted RPG‐deficient cells (cf. Narla & Ebert, 2010; Raiser et al, 2014 and references therein), namely a reduction in 41S species (18S‐E, 21S, and 41S) and an accumulation of 30S species (30S and 45S), indicating that heterozygous deletion of RPS6 impacts on ribosomal RNA biogenesis in ALL cells (Fig 3C and D).