ABC gene expression contributes to drug resistance of CD133(+) cells. (a) cDNA Microarray was performed on BAK MACS-sorted CD133(+) and CD133(-) cells using Affymetrix Chip, and raw data was accumulated and converted to normalized data by Partek Genomics Suites. (b) qRT-PCR verified fold change of ABC genes. BAK cells were exposed to the same concentrations of T in the presence or absence of 2 Î¼M elacridar (E; nontoxic concentration; Materials and Methods) and analyzed by XTT (c) or immunoblot analysis specific for phospho-MEK 1/2, total MEK1/2, and actin (e). (d) E dose response of BAK cells.