C3 (13% of all DLBCL) includes GCB-DLBCL with lesions affecting chromatin regulation (EZH2 mutations, KMT2D mutations, CREBBP or EP300 mutations or deletions), PI3K/AKT signaling (PTEN deletions or mutations, mTOR mutations, MIR17HG amplifications), apoptosis (BCL2 chromosomal translocations), cell motility (GNA13 mutations), and germinal center program (MEF2B or IRF8 mutations). The gene discussed is EP300; the disease is diffuse large B-cell lymphoma.