Expression pattern of the neuropilin-1 gene. RT-PCRs were performed using total RNA isolated from stromal cell lines (MS-5, 30E, 30W, and S17), adherent layers of long-term murine and human cultures (Mo Adh and Hu Adh), human fibroblasts (Fibro), and human CD34⁺/CD38⁻ (34+/38−) hematopoietic primitive cells. PCR products are 450 bp for human neuropilin-1 and 635 bp for murine neuropilin-1. As a control, amplification of RT products with either S14 primers (human samples) or HPRT primers (murine samples) is shown.