We recently observed that delayed tumour growth after local immunotherapy requires the presence of monocyte-derived dendritic cells. A role for monocyte-derived dendritic cells in anti-tumour immune responses had not been reported before and represents a potential exciting new advance for cancer immunotherapy. Harnessing the properties of these cells requires a better understanding of their differentiation and functions. We will employ strains of mutant mice to compare the relative contribution of monocyte-derived and conventional dendritic cells to anti-tumour immune responses. We will track the differentiation of monocytes into monocyte-derived dendritic cells in tumour-bearing mice, define their function in anti-tumour immunity, and identify the cytokines that support their differentiation in vivo. Lastly, we will examine the effects of hyperuricemia, which is linked to metabolic syndrome, on dendritic cell function and the impact of immunotherapies in vivo. We expect that this knowledge will lead to cancer immunotherapies that are more powerful and easily translated to clinical situations.