BCL6 and mature T-cell and NK-cell non-Hodgkin lymphoma: The specific immunomorphology of AITL is characterized by the simultaneous spatiotemporal proliferation of T follicular helper cells (CD4, CD10, Bcl-6, and PD-1), B cells (CD20 and EZH2), and follicular dendritic cells (CD21 and CD23), which can be distinguished from PTCL-NOS (12).