IL18 and macrophage activation syndrome: Furthermore, our transcriptome data showed that the CpG-induced transitioning monocytes and Mφs both display high expression of Il18. In addition, we found increased expression of Tnf and, to a lesser extent, of Il6, which is reminiscent of the interleukin (IL)-6+ and TNF-α+ Mφs found in liver biopsies of patients with cytokine storm syndrome (MAS).35