CDC27 is a core component of the anaphase-promoting complex/cyclosome (APC/C), a cell cycle-regulated E3 ubiquitin ligase that controls mitotic progression and G1 phase transition 1. The APC/C catalyzes formation of Lys-11-linked polyubiquitin chains and branched Lys-11/Lys-48-linked chains on target proteins 12. CDC27 is essential for proper mitotic timing; its mis-splicing delays G2/M transit and increases chemotherapy sensitivity 3. Beyond cell cycle control, CDC27 has emerged as clinically significant in multiple disease contexts. In systemic lupus erythematosus (SLE), CDC27 expression is downregulated in patient peripheral blood mononuclear cells and inversely correlates with disease activity markers; CDC27 shows 82.3% sensitivity and 94.4% specificity for SLE diagnosis 4. In hematologic malignancies, CDC27 is overexpressed in acute leukemias and represents a potential oncogenic biomarker 5. CDC27 O-GlcNAcylation regulates its protein stability in multiple myeloma through the autophagy-lysosome pathway, with therapeutic implications for combined proteasome-autophagy inhibition strategies 6. Additionally, CDC27 variants cause hemifacial microsomia through disrupted neural crest cell proliferation and chondrocyte differentiation 7, while CDC27 overexpression promotes gastric cancer metastasis via epithelial-mesenchymal transition 8.