It has also been reported that JAG1 overexpression by bystander and adjacent tumor cells leads to Notch1 activation and promotes cell growth in Hodgkin’s and anaplastic large cell lymphoma [31], suggesting that high expression of JAG1 might have a role in the activation of Notch1 in HTLV-1-induced leukemia. This evidence concerns the gene JAG1 and leukemia.