Similar to our observations in HTLV-1-infected cell lines, HERV-H Env, HERV-K (HML-6) Env, HERV-R Env, HERV-E gag HERV-K gag, and HERV-R pol transcript levels were statistically higher in ATLL patient cells compared to ACs (p = 0.0001) (Figure 3A–C,E–G). Here, ERV3-1 is linked to adult T-cell leukemia/lymphoma.