CD8A and neoplasm: On the other hand, the effects of CD8 depletion in untreated or OV-EGFP-treated WT mice were modest and did not reach significant levels compared with their respective isotype-treated controls, although small but transient inhibition of tumor growth within the first 10 days of OV-EGFP treatment was observed, likely because of the cytolytic effect of the virus on tumor cells regardless of T cell depletion.