polymorphisms affecting the activity of the multidrug resistance protein ABCB1 (MDR1), which is a major determinant of morphine bioavailability, can alter the efficacy of morphine pain relief [61], presumably by affecting the rate at which morphine and its metabolites are removed from the cell. Interestingly, not all genetic variations affect all pain modalities, meaning that these must be transduced by distinct pathways. The identification of genetic variations affecting propensity to pain raises the possibility of discovering new therapeutic targets for pain. By selecting those polymorphisms affecting pain sensitivity but not other processes such as cardiac function, the likelihood of identifying a specific, selective target will be enhanced. Future Prospects Substantial progress has been made in pain genetics recently. Just as a massive research attack on cancer genetics in the 1980s is References 1. Indo Y, Tsuruta M, Hayashida Y, Karim MA, Ohta K, et al. 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