In a separate study of 12 T790M+ patients who underwent tumor biopsy post-progression on rociletinib, 6 patients became T790M wild-type, 2 T790M wild-type cancers underwent SCLC transformation, 3 T790M-positive cancers acquired EGFR amplification, and 1 patient had T790 wild-type and mutant cell populations coexisting in the tumor (28). This evidence concerns the gene EGFR and neoplasm.