CD8A and neoplasm: But, tumor cells escape immune surveillance by reducing MHC class I production via mechanisms like genetic mutations or deletions in MHC class I processing components, such as beta-2 microglobulin, TAP1, and TAP2,11 or the downregulation of transcription factors like NLRC5 that are required for MHC class I expression.155 This results in diminished MHC class I expression, hindering CD8 T cell recognition and allowing tumors to evade immune destruction (Fig. 1).