The gene expression profile also contributes to the better definition of the boundaries between PTCL/NOS and angioimmunoblastic T cell lymphoma, the latter deriving from follicular T helper lymphocytes and characteristically expressing CXCL13 and PD1 along with vascular endothelial growth factor. Here, CXCL13 is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.