Punjabi microbiologist Surendra Nath Sehgal spent his life’s work studying a bacterium found in the soil on Easter Island. Called Rapamycin, it became a wonder drug, changing the lives of millions.

“Uma, it’s a fantastic compound, it’s a miracle,” Sehgal would tell his wife during these early encounters. “Anything it touches gives good results.”

Back in the lab, as Sehgal and his team were studying rapamycin’s antifungal properties, they realised it also had immunosuppressant qualities. This would make it very useful in countering the advance of autoimmune diseases such as rheumatoid arthritis and lupus. Crucially, it could help in post organ transplant recovery.

Cheri has been an editor at Longreads since 2014. She's currently based in the San Francisco Bay Area.