BTK and diffuse large B-cell lymphoma: Our results suggest that IQS019 can counteract both chronic and tonic BCR signaling, as it shows similar antiproliferative activity in DLBCL cell lines from both the GCB and ABC subtype, which are respectively dependent for their survival on tonic (Syk/PI3K-mediated) and chronic (Syk/Btk-mediated) BCR signaling [8, 32–34].