Enables DNA-binding transcription factor activity. Acts upstream of or within several processes, including heart looping; negative regulation of neuron differentiation; and neuron differentiation. Part of transcription regulator complex. Is expressed in several structures, including central nervous system; embryo mesenchyme; heart; skeletal musculature; and urinary system. Orthologous to human LBX1 (ladybird homeobox 1). [provided by Alliance of Genome Resources, Apr 2022]