Interestingly, Kir2.1 regulates cell proliferation and multidrug resistance (MDR) in both NSCLC and SCLC cells (Liu et al., 2015; Wu and Yu, 2019) and also represents a prognostic factor, being overexpressed in primary SCLC and correlating with stage and response to chemotherapy (Liu et al., 2015) (Tables 4, 5). The gene discussed is KCNJ2; the disease is non-small cell lung carcinoma.