The voltage-gated shaker-type potassium channels Kv1.3 and/or Kv1.5 are overexpressed in various primary cancer cells (e.g., B-CLL) and tissues as well as in cancer cell lines [149,153,154] and a negative correlation between Kv1.3 expression and sensitivity to cisplatin and ceramide was observed, indicating that with decreasing expression of Kv1.3, the resistance of the tumour cells against the cytotoxic drugs increases [154]. Here, KCNA3 is linked to B-cell chronic lymphocytic leukemia.