CBR3 and cardiomyopathy: (3) Some studies demonstrate an association of polymorphisms in the enzymes involved in the carbonyl reduction of anthracyclines and the cardiomyopathy risk: e.g., in children, homozygous carriers of the wildtype G-allele of the CBR3 polymorphism V244M (1096G > A), who reduce doxorubicin faster to doxorubicinol than the polymorphic variant, have an increased risk for cardiomyopathy at low-to-moderate doses of doxorubicin (Blanco et al 2008, 2012).