**9. Impaired dendritic cell activation and function**

Dendritic cells are the main antigen-presenting cells (APC) that play an important role in the activation of CD8+ T cells and NK cells and are considered the main tumor surveillance cells. Neoplastic cells employ mechanisms to escape the immune system. The activation and alteration of dendritic cells, such as an increase in the production of IL-10 that antagonizes their antigen-presenting action, inactivates dendritic cells and reduces their ability to stimulate other cells. They induce anergy to specific antigens. Another study suggested that the release of IL-6 in the tumor environment keeps the dendritic cells immature, worsening the prognosis of patients with several tumors, as in the case of melanoma [33].

The importance of dendritic cells has been further explored in antitumor immunotherapy, including the use of dendritic cells in the production of antitumor vaccines [34].
