To address whether adenosine mediates the suppressive function of activated CD28KOCD8+ T cells on CD8+ Teff anti-tumor activity in vivo, B16.gp33 tumor-bearing mice were given sorted CFSE-P14 CD8+ Teff cells pre-cultured with CFSE+CD28KOCD8+ T cells that were treated with or without inhibitors. Here, CD8A is linked to neoplasm.