In patients with CLL, treatment with ibrutinib has been shown to decrease regulatory T cells and modulate the cytokine and chemokine milieu in vivo through the decrease of several cytokines (including IL-10, IFNγ, IL-6, and TNFα) and chemokines (including IL-8, MCP-1, MIP-1α, and MIP-1β) [21, 22]. This evidence concerns the gene CCL2 and B-cell chronic lymphocytic leukemia.