Nguyen et al. found that inducible overexpression of the RNA binding protein LIN28B is sufficient to drive liver cancers in mice. Knocking down Lin28b increased overall survival and reduced tumour burden, indicating that LIN28B is also necessary for tumour maintenance. Igf2 mRNA binding proteins (IGF2BPs) are overexpressed in human liver tumours, and knockdown of Igf2bp3 markedly reduced cell proliferation. This reduction was even higher when LIN28B was overexpressed, suggesting that IGF2BP3 might act as a downstream effector of LIN28B and that these two RNA-binding protein families may work synergistically to promote liver cancer development.