Some are implicated in schizophrenia and bipolar disorders (Tkachev et al., 2003; Santos et al., 2012; Mukherjee et al., 2014) as is the case for myelin basic protein (MBP; Schoonover et al., 2004) and autotaxin (Fuss et al., 1997; Fox et al., 2003; Haas et al., 2004). This evidence concerns the gene ENPP2 and bipolar disorder.