UBR4 (Ubiquitin Protein Ligase E3 Component N-Recognin 4) is a member of the N-end rule pathway, a conserved ubiquitin-dependent system that targets specific proteins for degradation via the ubiquitin-proteasome system. As an E3 ubiquitin ligase, UBR4 plays critical roles in regulating protein turnover, cell cycle progression, apoptosis, and maintaining genomic stability. It is involved in diverse physiological processes, including neurodevelopment, muscle homeostasis, and cancer progression. UBR4 antibodies are essential tools for studying its expression, localization, and functional interactions in these contexts. Researchers use these antibodies in techniques like Western blotting, immunofluorescence, and immunoprecipitation to explore UBR4's involvement in diseases such as neurodegenerative disorders, muscular dystrophies, and malignancies. Due to UBR4's large molecular size (~600 kDa) and complex domain structure, generating specific antibodies requires careful epitope selection and validation. Commercial UBR4 antibodies are typically validated using knockout cell lines or siRNA-mediated knockdown to confirm specificity. Recent studies highlight UBR4's emerging roles in DNA repair, viral infection responses, and synaptic plasticity, driving increased demand for reliable antibodies to advance mechanistic and therapeutic research.