Cytotoxicity refers to the quality of being toxic to cells. It often describes the harmful effects that certain substances, such as drugs or chemicals, can have on living cells. This toxicity can lead to cell damage, dysfunction, or even cell death, which is particularly important in fields like pharmacology and toxicology. In medical research, understanding cytotoxicity is crucial for developing effective treatments, especially in cancer therapy. Some cancer treatments aim to selectively kill cancer cells while minimizing damage to healthy cells. Evaluating cytotoxicity helps researchers determine the safety and efficacy of new drugs before they are used in patients.