VSIR and acute myeloid leukemia: In other cell types studied – PMA-activated, granzyme B expressing Jurkat T cells with cytotoxic activity, cytotoxic CD8-positive TALL-104 cells, primary CD3-positive human T lymphocytes (in both cell types, the overall granzyme B expression level is high) and monocytic AML THP-1 cells [which, unlike cytotoxic T cells, do not express detectable amounts of granzyme B protein (9)] – VISTA expression was reduced.