CD4 and neoplasm: In contrast, when T-cells surrounded tumour cells in T-cell rich areas of NLPHL-pC/E and THRLBCL cases, they were occasionally all PD1 positive (and may have been labelled as “PD1-positive rosettes” by singleplex methods) but they were of heterogenous CD4+ or CD8+ phenotypes reflective of the wider microenvironment rather than a localised bona fide rosette.