PROM1 and melanoma: The percentage of the hematopoietic stem cells, defined as positive staining for CD34 and CD133, was significantly increased in in-transit metastasized melanoma (0.30 ± 0.10 %) and soft tissue sarcoma (0.48 ± 0.12 %) patients compared to the healthy controls (0.13 ± 0.04 %; P < 0.001 each, Fig. 1).