ERBB2 and mucinous adenocarcinoma: Notably, another study [23] argued that anti-HER3 targeted therapy might be effective for NRG1 fusion tumors since NRG1 binds ERBB3/HER3–ERBB2/HER2 heterodimers and activates downstream signaling; they provided evidence of a durable response in an NRG1-rearranged invasive mucinous adenocarcinoma of the lung treated with the anti-ERBB3 monoclonal antibody (GSK2849330) [23].