A hallmark of cancer is its ability to evade the immune system. It is why researchers are focused on finding new strategies and targets to jumpstart the immune system so it can mount a response against tumors. One such target is the inhibitory receptor T-cell immunoglobulin and mucin domain 3 (TIM-3), a protein that is overexpressed in many different types of cancer and is associated with poor patient outcomes. It is known to block the activity of immune cells, such as dendritic cells, but how remains unclear. In a new article published in the journal Immunity, Moffitt Cancer Center researchers show that TIM-3 inhibits the STING signaling pathway in dendritic cells, thereby blocking their ability to elicit an immune response.