- An additional DNA sample will be taken and analyzed for genetic polymorphisms. The influence of genotype on pharmacokinetics and metabolism will be investigated by appropriate statistical methods, including population pharmacokinetic analyses. Genes to study would include MDR1 and SLC22A16, both involved in the transport of doxorubicin and AKR1A1 and CBR1, both involved in the reduction of doxorubicin to doxorubicinol. Selected genotypes will be incorporated as covariates into the population pharmacokinetic models developed. The potential impact of genetic variation will be evaluated in the context of other sources of variability such as age, weight, gender etc