Stephanie van Hoppe

159 The impact of OATPs on disposition and toxicity of antitumor drugs; insights from KO and humanized mice humanized protein in the right cellular or organ compartment, one still is studying the behavior of this protein in the complex context of a mouse. This context may well differ in some relevant aspects for the parameter studied from the context in a human patient. This caveat should always be borne in mind, and ultimately only careful studies in patients can point out whether the insights and results obtained with the mouse models do also apply fully in humans. Having said that, we think that there are many additional interesting and promising research lines in cancer and general drug disposition and toxicology, but also in broader physiology, that can be exploredwith the current set of OATP1A/1Bmousemodels. Such possibilities can be even further expanded by creating new combinations with existing or newly generated knockout and transgenic mouse lines for other drug transporters and drug-metabolizing enzymes. Ac knowl edgemen t s Part of the work in the Schinkel group reviewed in this paper was funded by grant NKI 2007-3764 of the Dutch Cancer Society to A.H. Schinkel.