CAT and Miyoshi myopathy: In accordance with this assumption, Figure 8A,B and Figure S12A show that CD38 overexpression rapidly increased mitochondrial superoxide anions (MitoSox) in MM cells, which in turn resulted in oxidative damage accumulation, as shown by the increase in malondialdehyde (MDA) and the activation of two enzymes involved in the endogenous antioxidant defenses: catalase and glutathione reductase (Figure 8C and Figure S12B).