CD4 and lymphoma: To patients who were clinically suspected of lymphoma or had equivocal immunophenotyping but had no demonstrable diagnosis at the time of receiving the specimens, PD-1, TRBC1 and some T-cell markers (such as CD3, CD5, CD7, CD4, and CD8) were added to one tube for screening AITL when the MFC did not detect obvious phenotypic abnormalities using T- and B-cell lineage screening tubes.