Since EML4-ALK and NPM-ALK fusion proteins share the same functional ALK region, and given that the number of NSCLC patients treated with crizotinib is much higher than those affected by ALK-positive ALCL, it is possible that the same mutations conferring resistance to crizotinib identified in NSCLC patients, might also occur in ALCL cases and that the spectrum of mutations causing resistance to ALK inhibitors in NSCLC and lymphomas may at least in part overlap. This evidence concerns the gene EML4 and non-small cell lung carcinoma.