To further validate the RNA-seq results, we depleted MBD6 with two different CRISPR sgRNAs in three different human SCLC cell lines and performed individual real-time qPCR experiments to determine the mRNA levels of NEUROG2, DDC, FOXA2, NKX2-8, CDH7, NKX2-1, NXK2-2, and CDK18 genes (Fig. 4G, Additional file 2: Fig. S4G, H), which are all critical genes for SCLC development [17, 33, 34]. This evidence concerns the gene DDC and small cell lung carcinoma.