IL10 and mature T-cell and NK-cell non-Hodgkin lymphoma: Interleukin-10 is secreted by malignant T cells and promotes immune evasion in PTCL [22, 68], and its expression in CD4+ T cells is positively regulated by Ikaros [69], likely explaining the mechanism by which lenalidomide impairs IL-10 production in malignant T cells (unpublished observation).