NTF4-induced dimerization of the receptor tyrosine kinase NTRK2 (TRKB), similar to BDNF-induced dimerization, leads to trans-autophosphorylation of NTRK2. NTF4-induced phosphorylation of NTRK2 on tyrosine residue Y516 was demonstrated using mouse Ntrk2 (human Y516 corresponds to Y515 of mouse Ntrk2). As the electrophoretic migration pattern of Ntrk2 phosphorylated in response to NTF4 is indistinguishable from the electrophoretic migration pattern of Ntrk2 phosphorylated in response to BDNF, and identical downstream effectors are activated, it is assumed that NTF4 induces phosphorylation of NTRK2 on five evolutionarily conserved tyrosine residues in the cytoplasmic tail of NTRK2: Y516, Y702, Y706, Y707 and Y817 (Minichiello et al. 1998).