CD8A and neoplasm: Notably, the high expression of both CTLA-4 and PD-1 on CD8+ T-cells infiltrating the GM-CSF—treated tumors on both time points suggested that the tumor microenvironment remained highly immunosuppressive following cytokine treatment and thus implicates that administration of recombinant GM-CSF intratumorally may not be optimal for T-cell function.