EML4 and non-small cell lung carcinoma: Primary resistance is a rare condition, but according to case reports, primary resistance in patients with ALK-rearranged NSCLC is caused by ALK mutation [80], MYC amplification [81], EGFR mutation [82], a low mutant allele fraction (MAF) of the EML4-ALK-rearrangement [83], K-RAS mutations [84], and Bim deletion polymorphism [85].