KCNQ2 and bipolar disorder: Recent studies have shown that both the KCNQ2 channel mutants—associated with bipolar disorder—and wild-type KCNQ2 channels are phosphorylated by GSK-3β in vitro, at a site that requires PKA priming and is dephosphorylated by protein phosphatase 2A (PP2A; also known as calcineurin) (Borsotto et al., 2007).