In reconstructive and esthetic medicine, a technique called cell-assisted lipotransfer, i.e., the grafting of the patient's own adipose tissue to another site in the body after mixing with autologous stem cells, is being increasingly used and aggressively promoted. This technique has not been shown to yield better outcomes than conventional lipotransfer without cell enrichment. The vitally important matter of safety -- in particular, the question whether the added stem cells might promote tumor growth -- has not yet been settled either.