Clustering of CTCs obtained from ClearCell FX–Polaris system. (A–I) Visualization, clustering, and cluster purity of ClearCell FX–Polaris in presence of independent breast CTC and WBC scRNA-seq profiles, using Vanilla Seurat, fastMNN, and Harmony, respectively. (J–L) unCTC visualization, clustering, and cluster purity are depicted in equivalent figures. Notably, Vanilla Seurat, fastMNN, and Harmony failed to integrate CTCs from two different sources. unCTC accurately segregates CTCs and WBCs. CTCs obtained from ClearCell FX–Polaris system cocluster with breast CTCs from Ebright et al. data (Ebright et al. 2020).