We identify a number of genes as potential markers of intrinsic cisplatin refractoriness, such as DKK1, FMN1, XRCC2 and LGALS9. Moreover, we demonstrate that DKK1 is a possible target that can be used for cisplatin sensitizing purposes in NSCLC cells and likely also other tumor types such as ovarian carcinoma. Here, DKK1 is linked to ovarian carcinoma.