To investigate the molecular mechanisms underlying the emergence and maintenance of drug-tolerant (DT) cells in anaplastic lymphoma kinase (ALK)-rearranged lung cancer, we isolated DT cells from H2228 and A925L cells exposed to high doses of alectinib or lorlatinib for 9 days, and performed transcriptome analysis between parental and DT cells using a gene expression microarray. Overall design: H2228 and A925L cells which were untereated or treated with alectinib or lorlatinib for 9 days were selected for RNA extraction and hybridization on Affymetrix.