DKK1 and cancer: In order to initially assess a DKK1 RNAscope CISH assay, 4 cell lines (PC3, A549, HeLa, and Pfeiffer) that express a range of DKK1 were identified using publicly available RNA-Seq data from the Cancer Cell Line Encyclopedia (CCLE) database (Fig. 1a and Supplementary Table S1)33.