Specifically, the former had double the number of cytotoxic T-cells, which kill off body cells that are damaged, malfunctioning or infected with viruses.

The short, leafy plant was the original source of podophyllotoxin, a cytotoxic compound that’s the starting point for an anticancer drug called Etoposide.

Some of these so-called “élite controllers” possess cytotoxic, or killer, T cells that attack virus-producing cells.