Perhaps more relevant to human PTCL is the oncogenic driver, interleukin-2 inducible T-cell kinase-spleen tyrosine kinase (Itk-Syk) fusion protein which has been associated with a small number of cases of follicular-type PTCL and AITL [27,28]. Here, SYK is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.