The trimethylation of H3K27 that is almost completely abolished in the MCC promoter region in TRAF3−/− B lymphomas is intriguing, considering that the expression levels and activity of EZH2 of the polycomb repressive complex 2 (PRC2) catalyzing H3K27Me3 are often elevated in human B lymphomas and MM [45–47]. Here, MCC is linked to Miyoshi myopathy.