S100B and diabetes mellitus: Serum S100B is more specific for melanoma than serum LDH, however, serum S100B levels can be elevated in many other diseases, such as neurodegenerative diseases, previous stroke, migraine, acute brain injury, inflammatory bowel disease, liver cirrhosis, diabetes, cardiovascular diseases (8, 53), thus comorbidities may affect the prognostic value of serum S100B in patients with metastatic melanoma.