As downregulation of endogenous ASCL1 and NEUROD1 preceded the loss of viability and apoptotic cell death (Fig. 3h, i), we reasoned the repression of ASCL1 in SCLC-A cells and of NEUROD1 in SCLC-N cells to be potential causes of the detrimental effects on co-expression of NEUROD1 and ASCL1, respectively. Here, NEUROD1 is linked to small cell lung carcinoma.