We retrospectively analyzed patients with EML4-ALK positive advanced NSCLC who were treated with crizotinib from May 2012 to Aug 2013.    ///    We retrospectively analyzed patients with EML4-ALK positive advanced NSCLC who were treated with crizotinib from May 2012 to Aug 2013.     ///    The EML4-ALK fusion rate and number of prior chemotherapy cycles did not appear to significantly affect the efficacy of crizotinib. 