To examine the role of KMTs in regulating H3K4 methylation in prostate cancer, small interfering RNA (siRNA)-directed KMT2A knockdown showed an association with a decrease in H3K4me1 and H3K4me2 in C4-2B and DU145 cells, while it increased in 22Rv1 cells. The gene discussed is KMT2A; the disease is prostate carcinoma.