CCL2 produced in the tumor microenvironment is known to recruit tumor-associated macrophages (TAMs) [37], which are known to support the growth of neuroblastoma cells via production of IL-6 [38], to suppress antitumor immunity in cancer-bearing hosts via IL-10 production [39] and recruitment of regulatory T cells [40], and to promote tumor-supportive angiogenesis [41]. Here, IL6 is linked to neuroblastoma.