KCNJ3 and neoplasm: MCF-7 cells stably overexpressing KCNJ3 (MCF-7GIRK1a; [13]) formed significantly higher numbers of mammospheres compared to controls (p < 0.01; Figure 6), indicating that KCNJ3 upregulation might be involved in conferring self-renewal capacity to cancer cells and thus contributing to higher tumor aggressiveness.