CD14 is a glycosylphosphatidylinositol (GPI)-anchored receptor that may be expressed by cells of both hematopoietic and non-hematopoietic origin as a cell membrane or secreted protein. CD14 plays a key role in protecting the host against infections and in regulating cell metabolism in conditions predisposing to obesity. It acts as a co-receptor for the detection of bacterial lipopolysaccharide. It is essential for the host defense response in the lung against Gram-negative bacteria, such as nontypeable Haemophilus influenza and A. baumannii and E. coli.