2N6F576419242ENSG00000105894ENSMUSG00000029838P21246P63089NM_002825NM_001321386NM_001321387NM_008973NP_001308315NP_001308316NP_002816NP_032999Pleiotrophin (PTN) also known as heparin-binding brain mitogen (HBBM) or heparin-binding growth factor 8 (HBGF-8) or neurite growth-promoting factor 1 (NEGF1) or heparin affinity regulatory peptide (HARP) or heparin binding growth associated molecule (HB-GAM) is a protein that in humans is encoded by the PTN gene.

Pleiotrophin was initially recognized as a neurite outgrowth-promoting factor present in rat brain around birth[6] and as a mitogen toward fibroblasts isolated from bovine uterus tissue.

During embryonic and early postnatal development, pleiotrophin is expressed in the central and peripheral nervous system and also in several non-neural tissues, notably lung, kidney, gut and bone.

[10] In the adult central nervous system, pleiotrophin is expressed in an activity-dependent manner in the hippocampus[11][12] where it can suppress long term potentiation induction.

[14][15] or targeted neuronal damaged in the entorhinal cortex or in the substantia nigra pars compacta.