CD28 and neoplasm: Generally, it is believed that the T-cell anti-tumor efficiency primarily depends on the differentiation status of the adoptively transferred T cells, wherein T-cell differentiation is inversely correlated with the in vivo anti-tumor effectiveness.35, 36 The use of REP to expand TILs yields T cells with a loss of expression of CD28 and CD27;37, 38 these expanded TILs are prone to apoptosis and hypo-responsive to re-stimulation with tumor antigens.39 Instead of starting with TILs, T cells isolated from peripheral blood mononuclear cells were used for REP expansion in our current study.