GPRC5A and urinary bladder carcinoma: Gu identified that a CircRNA (hsa_circ_02838) is upregulated in human bladder tumors, and found that hsa_circ_02838 has peptide-coding potential and functions through a peptide-dependent manner; the peptide encoded by hsa_circ_02838 can bind to Gprc5a (a surface protein highly expressed in bladder cancer stem cells, driving bladder tumorigenesis and metastasis) and further enhance the function of Gprc5a to promote bladder cancer; thus, Gu termed hsa_circ_02838 as circGprc5a [14].