CD8A and neoplasm: This tumor-suppressive activity of S. aureus was corroborated in another TNBC model EO771, using PBS and S. mitis as negative controls (Fig. 5b).(35) Further investigation revealed that S. aureus-mediated inhibition of tumor growth was dependent on CD8+ T cells since this effect was nullified by antibody-mediated depletion of CD8+ cells but not CD4+ cells (Fig. 5c).