a, Schematic diagram of scRNA-seq workflow. b–d, The data of 34 patients generated using the 10X Genomics platform are shown. Number of cancer cells (n) and patients (P) with sensitive (S) versus resistant (R) tumors by arm; letrozole alone, n = 46,986, P = 11, S = 6, R = 5; intermittent high-dose ribociclib, n = 27,790, P = 12, S = 6, R = 6; and continuous low-dose ribociclib, n = 34,543, P = 11, S = 4, R = 7. The data of ten patients generated using the ICELL8 platform are shown in Extended Data Fig. 2. Distinction of different cell types is shown by a t-SNE plot of single cells of 34 patients with ER+ breast cancer (color represents cell type) (b). Gene copy-number profile in cancer cells and neighboring normal cells (c). Blue color indicates copy-number loss and red color indicates copy-number gain. Expression of marker genes of cancer cells and normal epithelial cells (KRT19, CDH1), stromal cells (FAP, HTRA1) and immune cells (PTPRC) (d). e, Proportion of cancer cells and neighboring normal cells in each patient.