The phrase "to become resistant" means to develop the ability or power not to be affected by something, especially an illness or a treatment. Full definition
Scientists have made an important breakthrough in understanding why some cancer cells become resistant to chemotherapy. (sciencedaily.com)
Key insights into how bacteria become resistant to antibiotics could reverse the process and renew the efficacy of commonly prescribed medications. (seeker.com)
People develop Type 2 diabetes when their bodies become resistant to the hormone insulin, which carries sugar from the blood to cells. (sciencedaily.com)