BTK and diffuse large B-cell lymphoma: The latter is predominantly associated with mutation of BTK and PLCG2. 6,7CARD11 mutation is identified in 10%-15% of DLBCL at presentation11 but is rarely identified (< 1%) in CLL.12 This suggests that the BCR signal in CLL and DLBCL may be qualitatively different and therefore that genetic mechanisms of resistance to BCR inhibition may also differ.