HNRNPU and cancer: Cross-linking RIP assay also indicated the abundance of circ-hnRNPU within NONO antibody-immunoprecipitated RNA in a variety of cancer cell lines (Additional file 1: Fig. S2c, d), while steady transfection of circ-hnRNPU facilitated its interaction with NONO, resulting in decreased binding of NONO to hnRNPU mRNA (Fig. 3c).