Sequencing of PIM1-CBRluc MFP tumors revealed maintenance of genomic architecture compared to the patient’s primary tumor biopsy and to early-passage PDX MFP tumors (Supplementary Figure 3-4), indicating that the bottleneck observed in barcoded MFP tumors relative to the pre-implantation reference cell pellet was not due to enrichment of a genomic subclone. The gene discussed is PIM1; the disease is neoplasm.