Research teams based in Germany and Spain have independently discovered that cells transmit inflammation by releasing ASC specks, bacteria-sized clumps of protein key for cytokines’ maturation, according to two papers appearing today (June 22) in Nature Immunology. The protein aggregations are a component of inflammasomes, which sense pathogens and cell damage and set off innate immune inflammation. Researchers previously thought inflammasomes acted only inside single cells, but this latest work has found that the ASC specks can effect extracellular inflammation. The teams also found that macrophages can take up released ASC specks, perpetuating the immune response.