SMPD3 and muscular dystrophy: Next, to analyze whether loss of the nSMase2/Smpd3 gene in the mdx background affects muscular dystrophy via muscle-abundant miRNAs, we quantified the levels of the myomiRs miR-1, miR-133a, and miR-206 in the GAS muscles of mdx and mdx:Smpd3−/− (#11 and #238) mice.