Furthermore, the most recent report from Barbagallo proposed that circSMARCA5, predicted to be enriched in the splicing factor Serine and Arginine Rich Splicing Factor 1 (SRSF1) protein-binding sites, acted as sponge for SRSF1 in GBM [63], raising some questions that whether this type of sponge function of RBPs is similar to circRNA-miRNA interaction and what characteristics should circRNAs have to bind to specific types of proteins or miRNAs. This evidence concerns the gene SLU7 and glioblastoma.