CD69 and breast cancer: Additionally, CD8+ T cells in the spleen, lung and BALF of Abx mice were less capable of expressing activation marker (CD69) or producing multiple effector molecules including IFN-γ and granzyme B, whereas BC colonization restored expression of CD69 and secretion of IFN-γ and granzyme B in all three tissues upon IAV PR8 infection at 8 dpi (Figure 3(c) and Figure S3d).