In L4 animals when VC neurite outgrowth is taking place,
fntb-1 promoter activity was found in VC neurons and vulval cells. In addition to VC neurons,
fntb-1 was expressed in motor neurons in the ventral nerve cord, mid-body region neurons (HSNs and CANs), and various neurons in the head and tail. In non-neural tissue,
fntb-1 expression was observed in body wall and pharyngeal muscle and rectal epithelial cells.