Cultured cells are cells that are grown under controlled conditions outside of their natural environment, typically in a laboratory setting. This process allows scientists to study the cells' behavior, growth, and responses to various stimuli. Cultured cells can come from various sources, including human tissues, animal tissues, or even plants. These cells are often used in research for drug development, disease modeling, and genetic studies. By using cultured cells, researchers can gain insights into cellular processes and test new treatments before moving on to clinical trials. This method is essential in fields like biotechnology and pharmacology.