Figure 1.

We hypothesize that a direct crosstalk between nerves and immune cells in cancer exists. This crosstalk might occur both at the systemic and within the tumor microenvironment (TME) (red box) levels. At a systemic level, the crosstalk may be mainly mediated by neurotransmitters and cytokines, but molecular mechanisms are needed to be further examined. At the TME level, the interplay between the three components can be either direct, through ligands, or indirect. We speculate that exosomes play an important role in this communication both at the systemic level and in the TME.