CNTN2 and adult T-cell leukemia/lymphoma: Tax is the dominant CD8+ T cell target antigen of HTLV-1[11, 12]: Tax escape mutations in the HLA-A2-restricted epitope Tax 11-19 are more frequent in individuals with the HLA-A2 allele[13], and Tax expression is frequently silenced in the expanded clone in ATLL by mutations in tax or methylation or deletion of the 5’LTR[14–17].