CTLA4 and neoplasm: We observed that in our in vitro generated tumor-microenvironment, CTLA4+ ‘exhausted’ T cells percentage were very low (<1%) as compared to FOXP3+CTLA4+CD8+ Treg cells (6.5%) (Fig. 1E) and this indicated that isolated CD8+CD25+CTLA4+ T cell population predominantly comprised of CD8+ Treg cells.