KCNJ2 and small cell lung carcinoma: Potassium voltage-gated channel subfamily J member 2 (KCNJ2)/Kir2.1 belongs to the inwardly rectifying potassium channel family, which regulates drug resistance and cell growth through mediating mitochondrial 37S ribosomal protein MRP1 (MRP1)/ATP binding cassette subfamily C member 1 (ABCC1) expression in small-cell lung cancer (22).