The Hiinkans are a humanoid species that are native to the planet Cerebus Prime.

At some point in the 23rd century, a plague broke out among the local population. Starfleet responded to the crisis by sending a large medical team, which included Dr. Mark Piper, to the planet to see if they could find a cure. Eventually, Piper succeeded in curing the plague, and he was given a latinum honor medallion in recognition of his efforts. By 2265, the Hiinkans had named three medical facilities in Piper's honor. (TOS - My Brother's Keeper novel: Constitution)