KCNA1 and neoplasm: Margatoxin (MgTx), an inhibitor of Kv1.3 (but also of Kv1.1 and Kv1.2; Bartok et al., 2014), when injected directly into the xenograft nude mice model of A549 human lung adenocarcinoma at 1 nM concentration, significantly inhibited tumor growth.