Corresponding m/z from collagen type I alpha 2 (COL1A2), cathepsin (CTSG), elongation factor 1-alpha 1 (EEF1A1), EH domain-containing protein 2 (EHD2), epiplakin 1 (EPPK1), prelamin-A/C (LMNA), and prolargin (PRELP) showed higher intensity distribution in HND in comparison to LND tumour areas. Here, CTSG is linked to tooth and nail syndrome.