SCN5A and cancer: Observations that Na+-channels are overexpressed in cancer cells [25, 26] suggests that increased influx may be the major driver of elevated [Na+]i, which is consistent with the overexpression of sodium channel protein type 5 subunit alpha (NaV1.5) [27] and other voltage gated Na+-channels [28] being associated with more rapid disease progression and worse patient outcomes [29].