Statistical analysis of variance (ANOVA; significant values p=< 0.05) revealed no significant differences in mean PO4-SMAD2 or PO4-SMAD3 histoscores analysed by patient sex, patient age, tumour pathological type (Table 1), tumour grade (Table 1 and Supplementary Figure 6A), tumour site (Table 1 and Supplementary Figure 5), the presence of peri-neural invasion (PNI) (Table 1 and Supplementary Figure 6B) or Clark level of invasion (Table 1 and Supplementary Figure 6C). This evidence concerns the gene SMAD2 and neoplasm.