 In 1996, mouse CRMP-4, often referred to as Ulip for Unc-33 like phosphoprotein, was discovered by Byk and colleagues, using a rabbit polyclonal antiserum which recognized a 64 kDa mouse brain specific phosphoprotein.In the same year, several other studies cloned CRMPs-1-4 in rat and dihydropyrimidinase (DHPase) homologous sequence of CRMPs-1, -2, and -4 in human fetal brain.Finally, in 2000, CRMP-5 was discovered using two-hybrid screenings of brain libraries or purification from a proteic complex.