IL1RN and neoplasm: The expression levels of Il1rn, which encodes IL-1RA and promotes tumour growth by inhibiting an inflammatory cytokine IL-1α32, and Cd274, which encodes programmed death ligand (PD-L)1 and kills T cells33, were similar between WT MDSCs and p16/p21-DKO MDSCs (Supplementary Fig. 3d).