CD8A and colorectal cancer: Interferon-γ is primarily produced by tumor-infiltrating CD8+ T cells and NK cells in colorectal cancer,38 and IFN-α boosts the function of CD8+ T cells and NK cells by increasing the expression levels of granzyme B and perforin.39 Similarly, we found significantly higher proportions of cytotoxic lymphocytes from MCP-counter analyses21 and measurements of cytolytic activity based on the transcript levels of GZMA and PRF131 among good responders compared with nonresponders.