Similarly, we have recently discovered that crenolanib, a known PDGFR inhibitor, acts on tumour endothelial cells, a mechanism that is not always directly related to its designated targets.38 Since resistance to sunitinib is a frequent event in the clinical management of RCC, one way to overcome this challenge is the optimisation of high-order drug mixtures to kill drug-resistant cancer cells.19,39 Notably, treatment with relatively low-dosed ODCs was effective also in cells chronically pre-treated with sunitinib. Here, PDGFRB is linked to renal cell carcinoma.