Neuregulin 4

Neuregulin 4 also known as NRG4 is a member of the neuregulin protein family which in humans is encoded by the "NRG4" gene.
Function.
The neuregulins, including NRG4, activate erb-b2 receptor tyrosine kinase 4 (ERBB4) to initiating cell signaling through cytosolic tyrosine phosphorylation.
Clinical significance.
Loss of expression of NRG4 is frequently seen in advanced bladder cancer while increased NRG4 expression correlates to better survival.