SPP1 and neoplasm: OPN modulates the generation of memory precursor effector CD8+ T cells by regulating cytokine milieu during the acute phase of virus infection [43] Moreover, Klement et al. demonstrated that downregulation of IRF8, a molecular determinant of apoptotic resistance in tumor cells and in CD11b + Ly6CloLy6G+ myeloid cells, aborted the repression of OPN.