The article discusses the complex interplay among various RNA species, including protein-coding mRNAs and non-coding RNAs such as long non-coding RNAs (lncRNAs), pseudogenes, and circular RNAs (circRNAs). These RNA transcripts act as competing endogenous RNAs (ceRNAs) or natural microRNA sponges, communicating and co-regulating each other by competing for binding to shared microRNAs. The authors highlight the importance of understanding this RNA crosstalk to gain insights into gene regulatory networks and their implications in human development and disease. Recent studies have shown that non-coding RNAs represent a significant portion of the human transcriptome, with numerous small RNAs, lncRNAs, and pseudogenes contributing to gene regulation. The article reviews the roles of RNA–RNA interactions, including the competition for miRNAs, and the involvement of RNA-binding proteins (RBPs) in post-transcriptional regulation. It also discusses the use of artificial miRNA sponges as tools to study miRNA competition and the discovery of natural miRNA sponges in various species, including plants, viruses, and humans. The authors emphasize the significance of ceRNA crosstalk in disease pathogenesis, particularly in cancers and developmental disorders. They highlight the importance of predicting and analyzing ceRNA interactions to understand their functional roles and potential therapeutic applications. The article concludes by discussing future perspectives, including the discovery of new classes of ceRNAs and the integration of ceRNA networks with other regulatory networks to fully appreciate their impact on biological systems and diseases.The article discusses the complex interplay among various RNA species, including protein-coding mRNAs and non-coding RNAs such as long non-coding RNAs (lncRNAs), pseudogenes, and circular RNAs (circRNAs). These RNA transcripts act as competing endogenous RNAs (ceRNAs) or natural microRNA sponges, communicating and co-regulating each other by competing for binding to shared microRNAs. The authors highlight the importance of understanding this RNA crosstalk to gain insights into gene regulatory networks and their implications in human development and disease. Recent studies have shown that non-coding RNAs represent a significant portion of the human transcriptome, with numerous small RNAs, lncRNAs, and pseudogenes contributing to gene regulation. The article reviews the roles of RNA–RNA interactions, including the competition for miRNAs, and the involvement of RNA-binding proteins (RBPs) in post-transcriptional regulation. It also discusses the use of artificial miRNA sponges as tools to study miRNA competition and the discovery of natural miRNA sponges in various species, including plants, viruses, and humans. The authors emphasize the significance of ceRNA crosstalk in disease pathogenesis, particularly in cancers and developmental disorders. They highlight the importance of predicting and analyzing ceRNA interactions to understand their functional roles and potential therapeutic applications. The article concludes by discussing future perspectives, including the discovery of new classes of ceRNAs and the integration of ceRNA networks with other regulatory networks to fully appreciate their impact on biological systems and diseases.