S100A8 and neoplasm: Myeloid cells have been implicated in therapy response through interactions with the malignant and endothelial cells, inducing chemoresistance via the CXCL1/2 – S100A8/9 loop, whereas tumor-associated macrophages have been linked to adverse outcomes and chemoresistance through survival factor secretion, anti-apoptotic pathway activation and modulation of signaling pathways [6][15][16].