ZNF609 is a zinc finger transcription factor that plays crucial roles in myogenesis and cellular proliferation. The gene produces both linear mRNA and a circular RNA (circ-ZNF609) through back-splicing 1. Functionally, ZNF609 is involved in the regulation of myoblast proliferation during muscle differentiation, with circ-ZNF609 specifically controlling this process 1. Remarkably, circ-ZNF609 contains an open reading frame and can be translated into a functional protein in a cap-independent manner, representing a rare example of a protein-coding circular RNA 1. The circular form encodes a 250-amino acid protein (ZNF609-250aa) that activates AKT3/mTOR signaling pathways 2. In disease contexts, circ-ZNF609 is aberrantly upregulated in various cancers including glioma, thyroid cancer, colorectal cancer, and esophageal squamous cell carcinoma 3456. The circular RNA functions as a molecular sponge for microRNAs (miR-150-5p, miR-378b, miR-514a-5p) and interacts with RNA-binding proteins like HuR to regulate target gene expression 634. Clinically, circ-ZNF609 promotes cancer cell proliferation, migration, invasion, and metastasis, making it a potential diagnostic biomarker and therapeutic target 78.