KCNMB4 and neoplasm: In tumor epithelial samples (light and dark blue in Figure 7), potassium voltage-gated channel subfamily A regulatory beta subunit (KCNAB2) and potassium calcium-activated channel subfamily M regulatory beta subunit 4 (KCNMB4) genes appeared upregulated, while KCNJ8 was also expressed in the stroma fraction (bright green bar in Figure 7).