PDGFRB and neoplasm: The cut-offs for tumor stromal PDGFRβ and non-malignant stromal PDGFRβ in the analyses was set to the third quartile, corresponding to 1.0 and 0.5 for tumour and non-malignant stromal PDGFRβ staining, i.e. high PDGFRβ immunoreactivity was ≥1.0 for tumour and ≥0.5 for non-malignant stroma.