Active BCR signaling can be detected using qIF of phosphorylated forms of BCR-associated kinases LYN, SYK and BTK in nearly 50% of DLBCL and can be used as a tool in formalin-fixed paraffin-embedded tissue samples to identify patients who may benefit from anti-BCR therapies [16,47,48]. This evidence concerns the gene BTK and diffuse large B-cell lymphoma.