We conceived a double approach to answer this question, based on a) permanent intracellular fluorescence labelling of cultured CAFs by the fluorochrome 5-chloromethylfluorescein diacetat (CMFDA); and b) detection of human CAFs in tumor tissue by a human-specific anti-PDGFRα antibody (Fig. 5A). The gene discussed is PDGFRA; the disease is neoplasm.