Predicted to enable DNA-binding transcription factor activity, RNA polymerase II-specific; RNA polymerase II transcription regulatory region sequence-specific DNA binding activity; and protein heterodimerization activity. Predicted to be involved in regulation of transcription by RNA polymerase II. Predicted to act upstream of or within embryonic pattern specification; lung development; and negative regulation of transcription by RNA polymerase II. Predicted to be located in nuclear body. Orthologous to human SIM2 (SIM bHLH transcription factor 2). [provided by Alliance of Genome Resources, Apr 2022]