Zolgensma is a gene therapy product that utilizes a non-replicating recombinant adeno-associated virus 9 (AAV9) vector to deliver a functional copy of the SMN1 gene under the control of the CMV enhancer/chicken-β-actin-hybrid promoter (CB) to express SMN1 in motor neurons of SMA patients. Here, SMN1 is linked to proximal spinal muscular atrophy.