May be involved in regulating the specificity of expression of the catecholamine biosynthetic genes. Involved in the development of several major noradrenergic neuron populations, including the locus coeruleus. Acts as a transcription activator/factor. Could maintain the noradrenergic phenotype (By similarity). . This is the function of PHOX2A (paired like homeobox 2A, Ensembl gene identifier ENSG00000165462).