Figure 1 Therapeutic targeting of the B-cell receptor (BCR) signalling pathway in patients with lymphoma Figure 1 | Therapeutic targeting of the B-cell receptor (BCR) signalling pathway in patients with lymphoma. a | BCR signalling pathway. Selective inhibitors for Syk and Btk are either approved by regulatory agencies or are in clinical trials. b | SYK structure. SYK is a non-receptor protein-tyrosine kinase containing tandem SRC homology 2 (SH2) domains. SYK inhibitors are able to competitively bind to the ATP-binding pocket of the kinase domain. Most BTK inhibitors bind covalently to cysteine 481 (C481) residues in the BTK active site, c | BTK structure . BTK is composed of four major domains: an N-terminal pleckstrin homology (PH) domain, a TEC homology (TH) domain, two SRC homology domains (SH3 followed by SH2), and a C-terminal kinase domain. d | A list of kinases that contain a C481 residue in the active kinase site. The IC50 is shown for ibrutinib using a purified kinase assay. Younes, A. et al. (2016) The landscape of new drugs in lymphoma Nat. Rev. Clin. Oncol. doi:10.1038/nrclinonc.2016.205