KMT2D and neoplasm: Our recent work on the chromatin modifier KMT2D using two SHH-MB mouse models showed that when one or two copies of Kmt2d are deleted, not only is there a nearly two-fold increase in tumor penetrance with a Classic tumor cytoarchitecture (highly proliferative), but strikingly a near 100% penetrance of spinal cord metastasis and hindbrain invasion7.