While still hotly debated in the neurobiology community, the use of neurons derived from induced pluripotent stem cells (iPSCs) has become almost commonplace.  Many labs are now employing human neurons to unravel disease mechanisms and to search for new therapeutics. But, do these neurons actually tell us anything we didn’t already know? I will present two examples from my lab. The first will be an iPSC-based dissection of the molecular basis of the childhood motor neuron disease Spinal Muscular Atrophy.  The second will be a study of the aging brain (in mice).