RNA binding proteins LIN28B and IGF2BP1/3 link PRC1/2 to HbF repression in adult erythroid cells. cPRC1 and PRC2 components are depicted as differently colored shapes, with the named components that were tested by Qin et al labeled. Silencing of LIN28B and IGF2BP1/3 in HUDEP2 cells or in adult primary cells is depicted by gray type. Depletion of BMI1 and CBX (cPRC1) or EZH2 (PRC2) relieves silencing of these RNA-binding proteins, thereby promoting silencing of BCL11A (gray type) or other events and upregulation of HbF. Professional illustration by Patrick Lane, ScEYEnce Studios.