CCDC12 (coiled-coil domain containing 12) is a nuclear protein that functions in both RNA splicing regulation and cellular differentiation processes. The protein localizes to the nucleoplasm and participates in spliceosomal complexes, where it regulates alternative splicing programs 1. In normal hematopoiesis, CCDC12 promotes early erythroid differentiation by upregulating erythroid markers including CD235, ε-globin, and γ-globin while modulating GATA-2 expression 2. However, CCDC12 exhibits oncogenic properties across multiple cancer types. In colon adenocarcinoma, CCDC12 promotes tumor development and invasion through the Snail pathway, affecting epithelial-to-mesenchymal transition 3. In breast cancer, CCDC12 upregulation enhances proliferation and metastatic potential by regulating RBM47 splicing, producing a truncated isoform with reduced tumor-suppressive activity 1. High CCDC12 expression serves as a poor prognostic marker in acute myeloid leukemia, correlating with shorter overall survival and treatment resistance 4. Additionally, CCDC12 hypermethylation in peripheral blood shows potential as a biomarker for breast cancer detection 5. The protein's dual role in normal differentiation and cancer progression suggests context-dependent functions requiring further mechanistic investigation.