Interstitial fluid pressure can be reduced by inhibition of phosphorylated platelet-derived growth factor receptor-β (p-PDGFR-β), a tyrosine kinase receptor frequently overexpressed in cancer stroma, and/or by inhibition of VEGF, a growth factor commonly overexpressed in tumours overexpressing p-PDGFR-β. The gene discussed is NTRK1; the disease is neoplasm.