Among these differentially expressed genes specifically linked to PML-RARA bound active APL-specific enhancers, were genes involved in myeloid differentiation and leukemogenesis, for example CEBPE, COL21A1, and PPARG. CEBPE is a critical transcription factor in myeloid cell differentiation [34] and leukemogenesis [35]. The gene discussed is COL21A1; the disease is acute promyelocytic leukemia.