CD8A and viral infectious disease: This complex understanding of the CDKN2A status under tumor conditions is matched with previous reports that studied CD8 T cell memory formation after the removal of chronic viral infection [88,89] where researchers found that despite the generated memory cells have shown phenotypic and transcriptional characteristics very close to the formed memory cell under acute infection models, the former cells were epigenetically scared and still have features of the exhausted CD8 T cells which affected the recall capabilities of these cells.