CD8A and cancer: In general, CD8+ cytotoxic T cells (CTL) and CD4+ helper T (Th)1 cells suppress cancer development through the production of interferons (IFN) and cytotoxins, but chronic inflammation that persists in colon cancer may override these effects and promote cancer development (Balkwill and Mantovani, 2001; Zamarron and Chen, 2011; Murata, 2018).