Consistent with this hypothesis, shRNAs targeting either Ptcd3, Mrps5 or Mrps27 (all encoding components of the 28S subunit) impaired proliferation of lymphoma cells (Figure 2A, 2B), delayed progression through all phases of the cell cycle (Supplementary Figure S2A for Ptcd3) and caused a slight increase in the number of apoptotic cells, as determined by Annexin-V staining (Figure 2C). Here, PTCD3 is linked to lymphoma.