Pharmacogenetics is a subset of pharmacogenomics which uses 
genomic/bioinformatic methods to identify genomic 
correlates, for example SNPs (Single Nucleotide 
Polymorphisms), characteristic of particular patient 
response profiles and use those markers to inform the 
administration and development of therapies. Strikingly, 
such approaches have been used to "resurrect" drugs thought 
previously to be ineffective, but subsequently found to 
work with in subset of patients. They can also be used for 
optimizing the doses of chemotherapy for particular 
patients.