In a phase I/II clinical trial study that involved 80 subjects with relapsed or refractory DLBCL, ibrutinib (PCI-32765), a BTK inhibitor, have shown a promising activity of ibrutinib as a single agent in the BCR- subtype of ABC-DLBCL; a 37 % ORR and a 16 % CR in relapsed/refractory DLBCL was reported for patients with the ABC- subtype compared with only 5 % of those with the germinal GCB subtype [235–238]. The gene discussed is BTK; the disease is diffuse large B-cell lymphoma.