What makes particular areas of immunology in vogue? And why do other aspects garner less enthusiasm by immunologists? One immune cell that seems to have suffered in the popularity stakes is the neutrophil. In his Review on page 173, Carl Nathan seeks to set this straight and to restore our enthusiasm for neutrophils by revealing their important role in informing and shaping immune responses. He aims to dispel the belief that their ability to cause tissue damage does more harm than good and to revise their definition as nonspecific mediators of inflammation. By putting them back in the limelight, he fosters the idea that neutrophils are potential targets to treat neoplastic, autoinflammatory and autoimmune disorders.

Although the Toll-like receptors are still very much in vogue, another family of microbial sensors has been growing in popularity — the CATERPILLER family. The CATERPILLER-family members have important roles in regulating innate and adaptive immune responses and might be important as intracellular sensors of microbial components. Enthusiasm for this family of proteins also stems from the observation that mutations in these proteins are associated with various inflammatory disorders, as described by Jenny Ting and colleagues on page 183.

Two other articles in this issue focus on complications of chronic inflammation. Francesca Aloisi and Ricarco Pujol-Borrell (on page 205) describe the formation, function and pathological significance of tertiary lymphoid structures that are frequently observed in tissues affected by chronic inflammation. And in the Opinion article on page 244, David Adams and Bertus Eksteen propose that extra-intestinal complications, such as inflammatory liver disease, in patients with inflammatory bowel disease result from aberrant recruitment of mucosal T cells from the gut to the liver.