CD8A and post-transplant lymphoproliferative disease: The combination of multi‐parameter cytokine secretion‐based phenotyping with t‐SNE analysis forms a powerful tool for dissecting subpopulations within the CD8+ cytotoxic T cell compartment, and was used as the basis for analysis of improvements and refinements in the manufacturing of the current SNBTS EBV‐specific T cell therapy used for treatment of PTLD [19].