ABCB1 and cancer: It contains a large number of structurally diverse diterpenes, which are responsible for the application of spurges in traditional phytotherapy.2 Several of these diterpenes were also identified as highly active inhibitors of the adenosine-5′-triphosphate (ATP)-dependent efflux pump p-glycoprotein, which is responsible for multidrug resistance in cancer.3 Given that resistance to prevalent drugs is one of the major drawbacks in the development of cancer therapeutics, progress in the synthetic preparation of Euphorbia diterpenes is also of medicinal importance.