CD8A and colorectal carcinoma: In order to determine whether NK cells make up a substantial proportion of the immune infiltrate of liver tumors, we compared their direct ex vivo frequency with those of CD8 T cells (CD3+CD56−CD8+), CD8 negative T cells (CD3+CD56−CD8−), and CD56+ T cells (CD3+CD56+) in blood, healthy liver margins, and HCC or CRC liver metastases.