On the other hand, the spatial distribution of Ctsk expression, which has been used as efficacy outcome after therapeutic intervention aiming to decrease dystrophic calcification46, has shown to be very specifically expressed in these calcified myofibers in the D2-mdx sample, suggesting that Ctsk could be a more specific marker of calcification/ossification than Bgn. Finally, osteopontin, the product of the Spp1 gene, has been linked to DMD pathology in different ways. The gene discussed is SPP1; the disease is Duchenne muscular dystrophy.