0 13 Heterogeneous heterogeneous JJ 14 24 expression expression NN 25 27 of of IN 28 40 Epstein-Barr epstein-barr JJ 41 46 virus virus NN 47 53 latent latent JJ 54 62 proteins protein NNS 63 65 in in IN 66 73 endemic endemic JJ 74 81 Burkitt Burkitt NNP 81 83 ’s 's POS 84 92 lymphoma lymphoma NN 92 93 . . . 95 107 Epstein-Barr epstein-barr JJ 108 113 virus virus NN 114 115 ( ( ( 115 128 EBV)-infected ebv)-infected JJ 129 134 cells cell NNS 135 138 may may MD 139 146 sustain sustain VB 147 152 three three CD 153 161 distinct distinct JJ 162 167 forms form NNS 168 170 of of IN 171 176 virus virus NN 177 184 latency latency NN 184 185 . . . 186 188 In in IN 189 203 lymphoblastoid lymphoblastoid JJ 204 208 cell cell NN 209 214 lines line NNS 214 215 , , , 216 219 six six CD 220 231 EBV-encoded ebv-encoded JJ 232 239 nuclear nuclear JJ 240 248 antigens antigen NNS 249 250 ( ( ( 250 255 EBNA1 EBNA1 NNP 255 256 , , , 257 258 2 2 CD 258 259 , , , 260 262 3A 3a NN 262 263 , , , 264 266 3B 3b NN 266 267 , , , 268 270 3C 3c NN 270 271 , , , 272 275 -LP -LP NNP 275 276 ) ) ) 276 277 , , , 278 283 three three CD 284 290 latent latent JJ 291 299 membrane membrane NN 300 308 proteins protein NNS 309 310 ( ( ( 310 314 LMP1 LMP1 NNP 314 315 , , , 316 318 2A 2a NN 318 319 , , , 320 322 2B 2b NN 322 323 ) ) ) 323 324 , , , 325 328 and and CC 329 332 two two CD 333 340 nuclear nuclear JJ 341 345 RNAs rna NNS 346 347 ( ( ( 347 352 EBERs EBER NNPS 352 353 ) ) ) 354 357 are be VBP 358 367 expressed express VBN 367 368 . . . 369 373 This this DT 374 378 form form NN 379 381 of of IN 382 389 latency latency NN 389 390 , , , 391 397 termed term VBN 398 405 latency latency NN 406 409 III iii CD 409 410 , , , 411 413 is be VBZ 414 418 also also RB 419 430 encountered encounter VBN 431 433 in in IN 434 438 some some DT 439 453 posttransplant posttransplant JJ 454 473 lymphoproliferative lymphoproliferative JJ 474 483 disorders disorder NNS 483 484 . . . 485 487 In in IN 488 500 EBV-positive ebv-positive JJ 501 506 cases case NNS 507 509 of of IN 510 517 Hodgkin Hodgkin NNP 517 519 ’s 's POS 520 527 disease disease NN 527 528 , , , 529 532 the the DT 533 538 EBERs EBER NNP 538 539 , , , 540 545 EBNA1 EBNA1 NNP 545 546 , , , 547 550 and and CC 551 554 the the DT 555 559 LMPs LMP NNPS 560 563 are be VBP 564 573 expressed express VBN 574 575 ( ( ( 575 582 latency latency NN 583 585 II ii CD 585 586 ) ) ) 586 587 , , , 588 595 whereas whereas IN 596 598 in in IN 599 606 Burkitt Burkitt NNP 606 608 ’s 's POS 609 617 lymphoma lymphoma NN 618 619 ( ( ( 619 621 BL BL NNP 621 622 ) ) ) 623 627 only only RB 628 631 the the DT 632 637 EBERs EBER NNPS 638 641 and and CC 642 647 EBNA1 EBNA1 NNP 648 652 have have VBP 653 657 been be VBN 658 666 detected detect VBN 667 668 ( ( ( 668 675 latency latency NN 676 677 I i CD 677 678 ) ) ) 678 679 . . . 680 682 We we PRP 683 687 have have VBP 688 695 studied study VBN 696 699 the the DT 700 710 expression expression NN 711 713 of of IN 714 717 EBV EBV NNP 718 726 proteins protein NNS 727 729 in in IN 730 732 17 17 CD 733 738 cases case NNS 739 741 of of IN 742 754 EBV-positive ebv-positive JJ 755 762 endemic endemic JJ 763 765 BL bl NN 766 768 by by IN 769 784 immunohistology immunohistology NN 784 785 . . . 786 796 Expression expression NN 797 799 of of IN 800 804 LMP1 LMP1 NNP 805 808 was be VBD 809 813 seen see VBN 814 816 in in IN 817 825 variable variable JJ 826 837 proportions proportion NNS 838 840 of of IN 841 846 tumor tumor NN 847 852 cells cell NNS 853 855 in in IN 856 859 two two CD 860 865 cases case NNS 866 869 and and CC 870 875 EBNA2 ebna2 NN 876 879 was be VBD 880 888 detected detect VBN 889 891 in in IN 892 896 some some DT 897 902 tumor tumor NN 903 908 cells cell NNS 909 911 in in IN 912 917 three three CD 918 923 other other JJ 924 929 cases case NNS 929 930 . . . 931 935 Also also RB 935 936 , , , 937 940 the the DT 941 946 BZLF1 bzlf1 NN 947 962 trans-activator trans-activator NN 963 970 protein protein NN 971 974 was be VBD 975 984 expressed express VBN 985 987 in in IN 988 989 a a DT 990 993 few few JJ 994 999 tumor tumor NN 1000 1005 cells cell NNS 1006 1008 in in IN 1009 1010 6 6 CD 1011 1016 cases case NNS 1016 1017 , , , 1018 1028 indicating indicate VBG 1029 1034 entry entry NN 1035 1039 into into IN 1040 1043 the the DT 1044 1049 lytic lytic JJ 1050 1055 cycle cycle NN 1055 1056 . . . 1057 1058 A a DT 1059 1069 phenotypic phenotypic JJ 1070 1075 drift drift NN 1076 1080 from from IN 1081 1088 latency latency NN 1089 1090 I i CD 1091 1093 to to TO 1094 1101 latency latency NN 1102 1105 III iii CD 1106 1109 has have VBZ 1110 1114 been be VBN 1115 1123 observed observe VBN 1124 1134 previously previously RB 1135 1137 in in IN 1138 1142 some some DT 1143 1145 BL BL NNP 1146 1150 cell cell NN 1151 1156 lines line NNS 1156 1157 . . . 1158 1161 Our our PRP$ 1162 1169 results result NNS 1170 1177 suggest suggest VBP 1178 1182 that that IN 1183 1184 a a DT 1185 1192 similar similar JJ 1193 1203 phenomenon phenomenon NN 1204 1207 may may MD 1208 1213 occur occur VB 1214 1216 in in IN 1217 1219 BL BL NNP 1220 1222 in in FW 1223 1227 vivo vivo FW 1228 1231 and and CC 1232 1240 indicate indicate VBP 1241 1245 that that IN 1246 1249 the the DT 1250 1261 operational operational JJ 1262 1272 definition definition NN 1273 1275 of of IN 1276 1279 EBV EBV NNP 1280 1289 latencies latency NNS 1290 1292 is be VBZ 1293 1296 not not RB 1297 1303 easily easily RB 1304 1311 applied apply VBN 1312 1314 to to TO 1315 1320 human human JJ 1321 1327 tumors tumor NNS 1327 1328 . . .