CP and small cell lung carcinoma: Remarkably, we noticed that the inactive form of SMYD3 was unable to induce cellular resistance to CP therapy compared with cells complemented with the WT SMYD3 (Fig. 1H), suggesting that the methyltransferase activity of SMYD3 is required to promote SCLC cells’ resistance to CP in vivo. Together, these results support a model where the function of SMYD3 is involved in SCLC response to alkylation therapy.