PDCD1 and angioimmunoblastic T-cell lymphoma: AITL has an immunophenotype closely akin to that of normal TFH; CD4+, CD8−, T-cell receptor (TCR) alpha/beta, and often expressing CXCL13, CD10, BCL6, Programmed-Death-1 (PD-1), ICOS, and CD2002,4–6.