ergothioneine
... that even one hundred years after its discovery, the role of the amino acid ergothioneine in the human body remains a mystery?
... that even one hundred years after its discovery, the role of the <a href="./Amino_acid" id="mwEF0" rel="mw:WikiLink" title="Amino acid">amino acid</a> <b id="mwEF4"><a href="./Ergothioneine" id="mwEF8" rel="mw:WikiLink" title="Ergothioneine">ergothioneine</a></b> <i id="mwEGA">(molecule pictured)</i> in the <a href="./Human_body" id="mwEGE" rel="mw:WikiLink" title="Human body">human body</a> remains a mystery?