Individualized drug sensitivity testing. Two different devices are illustrated that allow for in vivo drug sensitivity testing and biomarker analysis in patient tumors. (A) The Jonas et al. device is implantable and can test up to 16 different drugs simultaneously. (B) The Klinghoffer et al. device called CIVO microinjects up to eight different drugs or drug combinations before tumor sampling and has been tested in rodent and canine models and in human subjects. Various pharmacologic and pharmacodynamic markers were evaluated in both studies to demonstrate that the results correlated with clinical response to therapy. Reprinted with permission from Coombes RC, et al. Drug testing in the patient: toward personalized cancer treatment. Sci Transl Med. 2015:7;284ps10.