To better clarify the potential function of semaphorins in the pathogenesis of adult gliomas characterised by high migration potential, marked angiogenesis with endothelial proliferation, severe hypoxia and tumour necrosis, we analysed by quantitative real-time RT–PCR, the expressions of class-3 semaphorins (A–G) and their receptors NRP1 and NRP2 in 38 adult gliomas. The gene discussed is NRP1; the disease is glioma.