We had recently demonstrated that TNALP-deficient (Akp2−/−) mice, which mimic the phenotype of the severe infantile form of hypophosphatasia, can be treated by intramuscular injection of a self-complementary (sc) type 8 recombinant adeno-associated virus (rAAV8) vector expressing bone-targeted TNALP with deca-aspartates at the C terminus (TNALP-D10) via the muscle creatine kinase (MCK) promoter. The gene discussed is ALPL; the disease is hypophosphatasia.