CNTN2 and deltaretrovirus infections: This analysis allowed us (i) to identify a significant number of genes whose expression is commonly affected by all Tax proteins and hence characteristic of the HTLV infection, independent of the virus type; (ii) to identify a subset of genes which are specifically up-regulated by Tax-1 and Tax-3 and (iii) to demonstrate that Tax-3 and Tax-1 are closely related in terms of molecular signature on gene expression profiles.