KLK6 and metastatic neoplasm: For melanoma progression category (T3, T4 and MM), only genes ontologically-related to hKLKs (EVPL, KLK6, KLK7, KLK8, KLK13 and SERPINB13) showed a positive and high correlation coefficient (mean of 0.971) in T4 thick melanomas (depth > 4.0 mm), but not in metastatic tumors (MM).