complement cascade

This term is a specialized technical expression used exclusively within immunology and biochemistry. It describes a precise, sequential activation of proteins that enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism. The term implies a rapid, amplifying effect, where the activation of one protein triggers the next, similar to a falling row of dominoes.

Because it refers to a specific biological process, it is treated as a singular conceptual entity. In scientific literature, it is almost always used in the singular to describe the mechanism itself, though it can be pluralized when referring to different types of cascades (e.g., classical, lectin, and alternative pathways) occurring across different species or conditions.