ROR1 is uniformly expressed in B-CLL and shows expression in human ES cells. (A) ROR1 mRNA expression in B-CLL cells, normal primary and EBV-transformed B cells and a panel of normal hematopoietic and nonhematopoietic tissues was analyzed by qPCR. One B-CLL sample (B-CLL #1) was used as a reference (expression = 1), and the relative expression of ROR1 was compared with GAPDH as housekeeping gene. (B) Analysis of ROR1-protein expression on the cell surface of PBMCs obtained from B-CLL patients and normal donors using specific polyclonal antibodies (solid black line) compared with isotype controls (gray histogram). Data are representative for 10 B-CLL patients and 4 normal donors. (C) ROR1 expression on mature adipocytes that were generated in vitro by differentiation from human white preadipocytes, compared with B-CLL cells analyzed in the same experiment. (D) Expression of ROR1, SSEA-4, and SSEA-1 on the human ES cell line H1 before and after undirected in vitro differentiation for 6 and 12 days. Histograms show staining with specific monoclonal (SSEA-4/1) and polyclonal (ROR1) antibodies (solid black line) versus matched isotype control antibodies (gray histogram).