Role for NSD proteins as oncogenes in various cancer types. Overexpressed and/or deregulated NSD proteins (i.e., translocations) cause a switch from repressive H3K27 methylation to active H3K36 methylation. This leads to aberrant targeting of genes, causing unscheduled gene expression and subsequent tumorigenesis. AR, androgen receptor; RNAPII, RNA Polymerase II; AML, acute myeloid leukemia.