Pentraxin 3 (PTX3), also known as TNF-stimulated gene 14 (TSG-14), is a secreted glycoprotein belonging to the Pentraxin family of proteins. It is the prototypical long Pentraxin, exhibiting a C-terminal Pentraxin domain characteristic of the family, and a unique N-terminal domain. It is produced by several cell types including endothelial and mononuclear cells. PTX3 acts as a pattern recognition receptor with non-redundant roles in the innate immune response to several microbial agents including the fungal pathogen Aspergillus fumigatus. Overexpression leads to enhanced pro-inflammatory responses. PTX3 is induced in response to LPS and inflammatory cytokines including TNF-alpha and IL-1 beta.