CD8A and neoplasm: CD8 T cells and CD56 NK cells, frequently immune cells found in GIST, were significantly correlated with NIH risk (P < 0.001 and P = 0.001), tumor size (P = 0.004 and P = 0.004), mitotic count (P = 0.001 and P = 0.004), and local invasion (P = 0.028 and P = 0.015).