These results were confirmed by in vitro experiments showing that multidrug-resistant SCLC cell lines became more sensitive to doxurubicin, cisplatin and etoposide when Kir2.1 channels were knocked down, whereas Kir2.1 overexpression induced a desensitization of cells to these chemotherapeutic agents. The gene discussed is KCNJ2; the disease is small cell lung carcinoma.