Gold has excellent resistance to corrosion and bacteria. Also, its biocompatibility, as well as its hypoallergenic properties make it a "tool" in medicine.
Gold is used:
-in implants and pacemakers
-in dentistry
-in stents to block arteries
-in microchip drug delivery applications
-as a component of drugs in cancer and rheumatoid arthritis
-in a controlled injection of DNA on specific cells to enhance the reactions
in biochemistry.
And in many other applications that justifiably classify it as the king of metals!