scRNA-Seq of end-point primary tumors demonstrates heterogeneity in phenotype. (A) The tSNE of primary tumor cells across treated and untreated mice, colored by mouse called from k-nearest neighbors clustering. (B) tSNE of primary tumor cells across treated and untreated mice, colored by clusters. (C) Computational cluster assignments (SI Appendix, Supplementary Information Text) for 96-h CTCs next to their matched primary for a representative treated mouse and untreated mouse plotted as bar plots (n = 18 and n = 82 cells for treated mouse 1 96-h CTCs and tumor cells, respectively; n = 52 and n = 84 cells for untreated mouse 1 96-h CTCs and tumor cells, respectively). UA, unassigned. Neither pairing is significantly different (P = 0.99 and P = 0.66 for treated mouse 1 and untreated mouse 1, respectively, by Fisher’s exact test).