CD19 and neoplasm: In contrast, adoptive transfer of FACS-sorted CD19+/GFP+ B cells (Figure 1A and D) did not result in any incorporation of these cells into tumor lymphatic vessels (Figure S5), underscoring the exclusive ability of myeloid cells to contribute to tumor lymphangiogenesis and excluding the possibility that minor contaminations of hematopoietic stem cells in the FACS-sorted fractions may have contributed to the GFP+ cells that incorporated into tumor lymphatics.