ALK and non-small cell lung carcinoma: Of interest, NRG1 fusions have been proved to be coexistent with ALK fusion or RAS mutation in NSCLC patients both in primary and in metastatic sites of lung tumors [19, 22, 23] and it has been recently considered as a potential mechanism of resistance after treatment with crizotinib in ALK-rearranged NSCLC cell lines [24].