To study the impact of MLL/COMPASS on DNA methylation, we targeted WDR5, a component essential for all MLL/COMPASS complexes to bind the histone H3 N-terminal tail [27], for siRNA-mediated depletion using the human embryonic carcinoma cell line (ECC) NCCIT as a model system. The gene discussed is WDR5; the disease is embryonal carcinoma.