Cysteinyldopa, or 5-S-cysteinyldopa, is a catecholamine. Excessive cysteinyldopa in plasma and urine has been linked to melanoma. Cysteinyldopa is found in large amounts in the plasma and urine of patients with melanoma.
The compounds of every Wikipedia article carrying a Chembox or a Drugbox, refreshed daily, with the values their infoboxes give. The pages need JavaScript; the API does not.