PRR7 and neoplasm: Figure 4C shows the top 10 proteins listed from high to low. Among them, RNF2 (ring finger protein 2) caught our attentions. As a member of the polycomb group (PcG), RNF2 is widely involved in tumor development through epigenetic regulation (29). RNA pull-down and RIP experiments in 143B and U2OS cells further confirmed the interaction between PRR7-AS1 and RNF2 (Figures 4D–F). Strikingly, it was noticed that RNF2 expression levels remained unaltered after knockdown of PRR7-AS1 compared to control (Figures 4G, H).