MMSET (MM SET domain), also known as WHSC1 (Wolf-Hirschhorn syndrome candidate 1) or NSD2 (nuclear SET domain-containing 2) is a SET-domain containing HMTase (histone methyltransferase) that is involved in the recurrent chromosomal translocation t(4;14) resulting in IgH enhancer-driven overexpression of MMSET in up to 20% of MM [64]. The gene discussed is NSD2; the disease is Miyoshi myopathy.