DNA methyltransferase 1 (DNMT1) inhibitors are also important in the context of SCLC, as the combined inhibition of DNMT1 and pyrimidine synthesis was found to sidestep the need for p53-mediated apoptosis by promoting terminal neuroendocrine maturation, demonstrating efficacy against chemoresistant SCLC cell lines [194]. This evidence concerns the gene TP53 and small cell lung carcinoma.