100 Most Influential People in Healthcare - 2024

Castillo has led the largest union and professional association of registered nurses in the U.S. since 2018, when she became NNU’s first Latino executive director. Membership is almost at 225,000. This year, the organization has supported nurses in dozens of labor actions, including strikes in Louisiana, rallies in California, and union contract ratifications around the country. Castillo has been a vocal advocate for public health, nursing safety, and the power of storytelling to make change. She has expressed the need for caution about the use of artificial intelligence in healthcare, saying that the technology must not be used to replace nurses’ clinical judgment or make staffing decisions without human oversight. Before her role at NNU, she served as director of the Registered Nurse Response Network.