To evaluate the role of circPSMC3 in GC cells, three siRNAs against circPSMC3 were designed to silence circPSMC3 without influencing PSMC3 mRNA level in BGC823 and SGC7901 cells (Additional file 1: Figure S1b-1d) and finally si-circPSMC3#1 was chosen for the following experiment with its high inhibitory efficiency. This evidence concerns the gene PSMC3 and gastric cancer.