Detection of EBER1 expression by in situ hybridization. Purified populations of CD4⁺ T cells, CD8⁺T cells, CD16⁺ NK cells, and CD20⁺ B cells obtained from patient 1, 19 months before the development of lymphoma, were cytocentrifuged and hybridized with an alkaline phosphatase-conjugated EBER1 antisense oligonucleotide probe.