LMP-1 antisense oligodeoxynucleotide treatment inhibits proliferation of EBV-positive lymphoblastoid cells. Proliferation was assayed by [³H]thymidine incorporation in 2 EBV-positive lymphoblastoid cell lines (11-23 and X50-7) and an EBV-negative B-cell line (BJAB) after exposure to oligodeoxynucleotide (10 μmol/L in liposomes) for 48 hours. Values represent the mean ± SD of triplicate assays. (□) Antisense-treated; (▪) control oligodeoxynucleotide (SS1)-treated; (▨) untreated control. P values for the mean difference between antisense and SS1-treated cells are as follows: 11-23, P < .002; X50-7, P = .0003; BJAB, P> .8. P values for the mean difference between SS1-treated and untreated cells are as follows: 11-23, P > .1; X50-7,P > .08; BJAB, P > .06.