BCL2 and aneurysmal bone cyst: MYD88 mutations in the MCD/C5 ABC-DLBCL often occur in combination with BCL2 copy number gains, and indeed, in the Myd88L252P mouse model, the combination with Cd19-Cre driven overexpression of BCL2 led to a significant increase in ABC-DLBCL-like B cell lymphomas (102).