The present invention is based on a novel, alternatively spliced human isoform of MD-2 (MD-2s). In addition, the present invention relates to modified MD-2 proteins, wherein one or more tyrosine residues have been mutated to phenylalanine. In various embodiments, the invention relates to methods and kits for preventing, reducing the likelihood of developing and/or treating various conditions using MD-2s. The invention also describes methods of determining the risk of a subject to various conditions.
