Alignment of amino acid sequences homologous to HTLV-1 BA21 Env peptide (A) and HTLV-1 p24 Gag peptide (B). Corresponding areas of conservation in HTLV-2 Env and HERV-K10 Pol or HTLV-2 p24 Gag and HERV-K10 Gag are indicated by the (•) symbol. Amino acid changes are as shown. The underlined peptide in HTLV-1 Env had been previously mapped to be the target of anti-HTLV-1 p21 Env seroreactivity in LGLL patients. The underlined peptide in HERV-K10 Pol and that shown for HERV-K10 Gag were used in the studies described herein. The GenBank accession numbers for various sequences are: HTLV-1 Env AAA96674; HTLV-2 Env AAZ16506; HERV-K10 Pol P10266; HTLV-1 Gag AAA85325; HTLV-2 Gag P14077, and HERV-K10 P87889.