In particular, tumor-reactive markers CD39 and CD103 were specifically demethylated in tumor-reactive CD8+ T cells, along with other signature genes for cytotoxic T cells, such as PRF1, IGNG, GZMB, CCL3, CCL4, NKG7, and CST7. Unsurprisingly, the status of DNA demethylation of these immune-related genes demonstrated dynamic changes as naïve T cells develop into tumor-reactive CD8+ T cells[86]. The gene discussed is PRF1; the disease is neoplasm.