NRG1 fusion-driven tumors: biology, detection, and the therapeutic role of afatinib and other ErbB-targeting agents

•NRG1 fusions result in ErbB-mediated pathway activation and present a rational therapeutic target.•ErbB-targeted treatments, such as afatinib, can be effective therapeutic options in tumors harboring NRG1 fusions.•The incidence of NRG1 fusion-driven tumors is low, occurring in <1% of cancers, but is highest (≈10-30%) in invasive mucinous adenocarcinoma. Oncogenic gene fusions are hybrid genes that result from structural DNA rearrangements,...