RHOBTB3 and neoplasm: To further confirm circular characteristics of circRHOBTB3, the transcripts of both circRHOBTB3 and RHOBTB3 mRNA was tested by qRT-PCR in three tumor tissues, AGS and HGC27 cell lines after treatment with or without RNase R. Results showed that the fragment of linear form of RHOBTB3 gene was digested by RNase R while cirRHOBTB3 was retained after RNase R treatment (Fig. 2a, b), which verified that circRHOBTB3 was resistant to RNase R due to its loop structure.