Table 1. Influence of ABCB1 1199G>A polymorphism on drug transport and/or efficacy.

Compound	1199A activity* (in vitro assay)	Clinical observations in 1199A carriers	References
Rhodamine	=  or ↓ (fluorescence)	n.a.	23 & herein
Doxorubicin	=  (cytotoxicity)	n.a.	13 & herein
Vinblastine	↑ (cytotoxicity)	n.a.	13 & herein
Vincristine	↑ (cytotoxicity)	n.a.	13
Paclitaxel	↑ (cytotoxicity)	n.a.	13
Etoposide (VP-16)	↑ (cytotoxicity)	n.a.	13
HIV protease inhibitors	↑ (accumulation)	n.a.	24
Cyclosporin A	=  or ↑ (accumulation)	Lower concentration in PBMCs	31 & herein
Tacrolimus	↓ (accumulation)	Higher concentration in PBMCs and hepatocytes	29-30 & herein

*Compared to 1199G wild-type; n.a.: not available.

See text for details.