Argonaute-2 (AGO2) is a pivotal protein in the RNA interference and microRNA pathways, known for its role in gene regulation through the binding and cleavage of target mRNAs, which it achieves by forming the RNA-induced silencing complex (RISC) with small RNAs such as siRNA and miRNA. This process is essential for post-transcriptional gene regulation, immune defense, and plays a significant role in various biological processes including development, cell differentiation, and tumorigenesis.