Friend and foe, HNRNPC takes on immunostimulatory RNAs in breast cancer cells

The RNA-binding protein HNRNPC is highly expressed in breast cancer, but its contribution to tumorigenesis was unclear. In this issue, Wu et al (2018) demonstrate that elevated HNRNPC is essential for the proliferative ability of two breast cancer cell lines. Reducing HNRNPC results in the accumulation of short Alu-derived dsRNAs that bind RNA receptor RIG-I and stimulate the production of IFN, a cytokine with known antiproliferative activity.