Notably, dual RNA-FISH and immunofluorescence, real-time qRT-PCR, and western blot assays indicated that stable over-expression or knockdown of circ-hnRNPU, but not of lin-hnRNPU, led to obvious cytoplasmic retention or absence of NONO in gastric cancer cells, without alteration in NONO transcript or protein levels (Fig. 3f-h, Additional file 1: Fig. S2e). This evidence concerns the gene HNRNPU and gastric cancer.