Antimicrobial resistance (AMR) is a topic that just won't go away, and for good reason. Despite the plethora of threats facing humankind, including thousands of diseases in need of therapies or cures, many scientists worry that the biggest risk of extinction comes from the deadly pathogens that exist in uneasy cohabitation on planet Earth. Tensions mounted in 2015 after the mcr-1 gene was detected on plasmids in China and Europe and were heightened last year with the first U.S. case of a patient with an infection resistant to a last-resort antibiotic.