A final demonstration of the expression of SULF1 in fibroblasts comes from our PDX studies of 42 HNSC patients (Figure 5) showing that in all but one case the expression of SULF1 decreases in the PDX compared with the primary tumor (median primary tumor TPM = 52.6, median PDX TPM = 1.7, p < 0.001; Wilcoxon rank-sum test). The gene discussed is SULF1; the disease is neoplasm.