A common observation, repeatedly reported over many years, in many tumour cells with acquired resistance to cisplatin is that of reduced platinum accumulation in comparison to the parental cells.[10] However, until recently, the underlying complex molecular mechanism by which cisplatin enters cells remained poorly defined. Cisplatin is highly polar and enters cells relatively slowly in comparison to other classes of small-molecule cancer drugs. The uptake of cisplatin is influenced by factors such as sodium and potassium ion concentrations, pH, and the presence of reducing agents; and a role for transporters or gated channels has been postulated in addition to passive diffusion[11] (Fig. 1). In the past few years, the major plasma-membrane transporter involved in copper homeostasis, copper transporter-1 (CTR1), has also been shown to have a substantial role in cisplatin influx.[12,13] Ctr1-/- mouse embryonic fibroblasts that were exposed to a clinically relevant concentration of 2 μM cisplatin or carboplatin accumulated only around 35% of the amount of platinum that was taken up by Ctr1 wild-type cells; loss of CTR1 also led to a 2-3-fold increase in drug resistance.[14] Both copper and cisplatin (at clinically relevant concentrations) cause a rapid downregulation of CTR1 expression in human ovarian cancer cell lines; this occurs through the internalization of CTR1 from the plasma membrane by macropinocytosis, followed by proteasome-based degradation.[15]