CXCR4 and neoplasm: To further validate the CNV calling in single cells, we performed a highly sensitive and quantitative ddPCR assay, and we confirmed the copy-number gain of Ppm1d (Fig. 5e) and Cxcr4 (Fig. 5f) in mouse tumors, but not in mammary glands of the same mouse, and the gain of ARHGEF11 and PPMD1 in TM00091 tumor from human (Fig. 5g) with Rpp30/RPP30 as a reference.