UBE2H is an E2 ubiquitin-conjugating enzyme that accepts ubiquitin from E1 complexes and catalyzes its covalent attachment to target proteins 1. The enzyme specifically partners with the GID/CTLH E3 ubiquitin ligase complex, with this E2-E3 pairing regulated by multisite phosphorylation of UBE2H at CK2-targeted acidic sequences that anchor to basic patches on the E3 complex 2. UBE2H is capable of catalyzing both K11- and K48-linked polyubiquitination in vitro and can ubiquitinate substrates including focal adhesion kinase (FAK) during skeletal myogenesis 1. The UBE2H-CTLH complex plays crucial roles in erythroid maturation, where dynamic expression changes control orderly progression of human erythropoiesis, and in antimicrobial defense, where the complex suppresses host responses against intracellular bacterial infections like Mycobacterium tuberculosis 34. Clinically, UBE2H mutations are associated with neurodevelopmental disorders - a de novo missense variant (p.Thr150Met) was identified in a patient with developmental delay and intractable seizures, and zebrafish studies confirmed UBE2H's essential role in normal brain development through regulation of the ATM-p53 signaling pathway 5. Additionally, genetic association studies suggest UBE2H may contribute to autism susceptibility and oxaliplatin resistance in colorectal cancer 67.