IC50 values refer to the concentration of a substance (typically a drug or inhibitor) required to inhibit a biological process or response by 50%. This measurement is crucial for understanding the potency and efficacy of drugs, especially in pharmacological research. The IC50 value is a quantitative measure that helps in determining how much of a particular inhibitory substance is needed to inhibit a specific biological activity in vitro. It's widely used in drug development and research to assess the effectiveness of new compounds, providing a standardized way to compare the inhibitory power of different substances.