S100A9 and central nervous system cancer: S100A9 is implicated in the activation of NLRP3 inflammasome in response to various pathological conditions such as DAMPs-mediated inflammation.44 This activation increased the secretion of pro-inflammatory cytokines (IL-6, IL-1β, and TNFα) and chemokines (IL-8, Gro-α, and MIP-1α/β) that are prevalent in gliomas.45 In this report, we have defined a gene expression signature of inflammation linked to S100A9/CLEC5A positive MDSCs whose genes are expressed in necrotic areas of the tumor.