Functions as a transcriptional regulator. May function as a transcriptional repressor. Functions in the differentiation and the maintenance of the central serotonergic neurons. May play a role in cell growth. Expressed in central serotonergic neurons. First expressed at 11 dpc in the rostral cluster of serotonergic neurons. During development, expression is restricted to serotonergic neurons located in the raphe nuclei. Mice display heightened aggressive and anxiety-like behaviors. They also display an extended and exacerbated period of breathing instability immediately after birth which results in an increased risk of death. This is associated with loss of the differentiation of a large number of the serotonin (5-HT) neurons without major structural abnormalities of the brain. Belongs to the ETS family.