It is worth noting that the expression of the same biomarkers from different tissues may vary; for example, a recent meta-analysis has shown a significant decrease in SOD levels in both erythrocyte samples and tissue samples in individuals with oral cancer (OSCC) compared to the normal control group, whereas the opposite was true in salivary samples, which demonstrated a significant increase in SOD levels in cancer patients [34]. Here, SOD1 is linked to lip and oral cavity carcinoma.