Organization of the HERV-E inserted into the human cd5 gene. (a) HERV-E.CD5 is found in humans, but not in mice. The enhancer (E), the LTRs, and the first CD5 exons are boxed. (b) The 5254-nt HERV-E.CD5 is depicted from 5′ to 3′: the putative U3, R, and U5 regions, the Cap signal, the tRNAGlu pbs, the splice donor (SD), the splice acceptor (SA), and the poly(A) signal (pA) are arrowheaded. (c) RT-PCR products were obtained in pre-B 697 cells using the exon 1B-CD5 sens primer, and reverse primers used are, respectively, 11q 12.2 gag, 11q 12.2 pro, 11q 12.2 env, and CD5 E5-6 (Table 2).