To measure expression changes in klf2, klf4, lif, and lin28b in neuroblastoma upon N-myc depletion, quantitative RT-PCR (qRT-PCR) was conducted on the cells treated with the same type of 3, 5, and 7-day time-course of Tet treatment that was used for the expression microarray (Fig. 2). This evidence concerns the gene KLF4 and neuroblastoma.