Using a colitis and tumor vaccination model, a group showed that mast cell‐derived AREG potentiates the immunosuppressive competency of regulatory T (Treg) cells, thus establishing a link between mast cells and Treg cells in the TME and suggesting a potential value of perturbing the associated mechanism to improve therapeutic efficacy of EGFR‐targeting agents in cancer clinics (Zaiss et al., 2013). The gene discussed is EGFR; the disease is neoplasm.