text: Yo, listen up, I got some knowledge to drop,
  About axon guidance and midline crossing, nonstop.
  Commissural neurons, they know the way,
  The molecular logic, let me convey.
  
  Development's the game, we're talkin' 'bout the start,
  But the genetic programs, they're still a dark art.
  Can one transcription factor, alone in the mix,
  Activate the programs for midline tricks?
  
  In the mouse, Dbx1's the factor we see,
  Expressed in progenitor cells, it's the key.
  Commissural neurons, they come from this crew,
  In the dorsal midbrain, they make their debut.
  
  Gain or loss of function, we put it to the test,
  Dbx1 alone, does it pass the midline quest?
  It's sufficient and necessary, we found,
  To trigger midline crossing, it's profound.
  
  Robo3 steps in, as a downstream player,
  Controlling midline crossing, a crucial layer.
  Dbx1-activated programs, they pave the way,
  For the wiring laterality, they have their say.
  
  But that's not all, Dbx1's got more to do,
  Suppressing ipsilateral neuron's program, it's true.
  A single transcription factor, that's Dbx1's role,
  Establishing wiring laterality, taking control.
  
  So remember this rap, when you think about the brain,
  Dbx1's the factor, driving midline's domain.
  Axon guidance, commissural neurons in the mix,
  Dbx1's the key, establishing that wiring fix.