UBE2B (ubiquitin conjugating enzyme E2 B) is an essential E2 ubiquitin-conjugating enzyme that transfers ubiquitin from E1 activating enzymes to E3 ligases, facilitating protein ubiquitination through multiple linkage types including Lys-11, Lys-48, and Lys-63 1. The enzyme forms critical functional complexes with E3 ligases, including RAD18 for DNA damage tolerance and PCNA mono-ubiquitination 2, and UBR4 for N-degron pathway protein degradation 3. UBE2B plays a crucial role in male fertility, as knockout mice exhibit infertility with reduced sperm motility and abnormal sperm morphology 4. Multiple studies have identified UBE2B genetic variants associated with human male infertility, including novel SNPs that may affect splicing and gene expression 56. In cancer biology, UBE2B demonstrates oncogenic properties in esophageal carcinoma, promoting cell proliferation and migration while serving as a potential prognostic biomarker 7. The enzyme also regulates ovarian cancer growth by promoting RAD18-mediated ZMYM2 monoubiquitination and protein stabilization 8. Additionally, UBE2B shows potential as a tuberculosis diagnostic biomarker through alternative splicing patterns that respond to mycobacterial stimulation 9. These diverse roles highlight UBE2B's importance in cellular homeostasis, DNA repair, reproduction, and disease pathogenesis.