Acts as a transcriptional activator or repressor. Implicated in the regulation of cell-type specific gene expression and play a role in inductive events during lens development. Homodimer or heterodimer with other bHLH-Zip transcription factors. Binds DNA as a homodimer or a heterodimer (By similarity). Expressed in the anterior neuroectoderm at stage 14. Expressed during the formation of the neural tube in rhombomeres (r) 5 and 6, in the derivative neural crest cells and then in the dorsal half of neural tube of r5 and r6 at stage 24. Expressed in the presumptive blood islands at stages 22 and 24. By stage 28 its expression in r5 disappears, but becomes detectable in r4 at stages 29 and 30. Its expression in r6 persists until stages 33 and 34. Expressed through r4 in two bilaterally symmetrical columns of cells in the dorsolateral spinal cord at stage 32. Expressed in developing somites at stages 33 and 34. Expressed in myotomal cells at stage 32. Expressed in the pronephros at stage 28. Expressed in the presumptive lens-forming ectoderm (PLE) at stage 22 and during lens formation. Expressed in the inner (sensorial) layer of PLE, developing lens placode and lens epithelium. Expressed in the anterior part of lens vesicle at stages 32 to 34. Belongs to the bZIP family. Maf subfamily.