In HCC patients, this process is hindered as tumor cells release cytokines and chemokines that recruit high levels of CD4+CD25+FoxP3+ regulatory T cells, which are accompanied by a decrease in CD8+ T cell infiltration at the tumor sites and a significant reduction in CD8+ T cell expression of granzyme A, granzyme B, and perforin. The gene discussed is GZMA; the disease is neoplasm.