CD8A and melanoma: Pharmacologic inhibition of the β-catenin/TCF pathway that promotes melanoma-associated DC production of retinoic acid has also been shown to reduce the expression of vitamin A-metabolizing genes in DC isolated from tumor-draining lymph nodes, and the antitumor activity associated with this inhibition correlated with reduced Treg and increased effector CD8+ T cell infiltration of subcutaneous melanomas (120).