The day she arrived at the laboratory and saw that the mice were moving again, Zaida Álvarez (Barcelona, 1984) could not help but shudder. Behind her lay more than six years of research, from Monday to Sunday, and a risky bet to outsmart evolution and repair the irreparable: the central nervous system of a mammal. "It was mind-blowing. Those animals, which had a severe spinal cord injury and were paralyzed, were walking again," she recounts, still moved, this bioengineer and researcher at the Institute for Bioengineering of Catalonia (IBEC).

Thalidomide It has gone down in history as one of the worst cases of devastating side effects caused by a drug. Although there is no official figure for how many people were affected globally, it is estimated that more than 10,000 babies were born with terrible birth defects during the years this drug was marketed.