Comparative sequence analysis of EBNA-1 from peripheral blood CD4⁺ T cells and lymphoma specimens. An EBNA-1 carboxy terminal fragment comprising nucleotides 1341-1671 (330 bp fragment) was PCR-amplified with DNA extracted from peripheral blood CD4⁺ T cells from patient 1, from two lymphoma specimens from patient 1 (distinct lymph nodes tumors 1, and 2), and from a lymphoma specimen from patient 2 (spleen, tumor 3). Shown are the results of direct sequencing of EBNA-1 codons 475 to 490. Nucleotide substitutions compared to the prototype EBNA-1(B95-8) are highlighted in bold. Multiple substitutions at the same position are indicative of multiple EBNA-1 variants.