We have shown ruxolitinib reverses inhibitory effects of cytokines on TLR‐signaling in CLL cells.4 Consequently, if ruxolitinib is given to patients with a high tumor burden, it may cause enhanced TLR‐signaling in these cells with the production of cytokines such as TNFα that could inhibit erythropoiesis in the bone marrow.27 We speculate this mechanism was not very active in this trial because the number of CLL cells was low and TLR‐signaling was prevented by the presence of ibrutinib. The gene discussed is TNF; the disease is neoplasm.