ELF2 and neoplasm: Finally, a bovine B-cell/ATL tumour pair had integration sites 17 and 13 kb from the same host gene, respectively (T15, ATL4_2, TMEM67), while an ovine B-cell/ATL tumour pair had their proviruses integrated within and 430 kb downstream of the same host gene, respectively (M395/ATL25_10, ELF2).