What are ASC oligomers?

An ASC oligomer is an ASC (apoptosis-associated speck-like protein with a caspase-recruitment domain) that has transformed and re-nucleated into a new, typically larger structure in response to a pathogen or other inflammatory stimulus. It is an innate part of the biochemical system collectively known as the inflammasome. The newly formed ASC oligomer activates enzymes such as caspase-1, which then causes a myriad of other downstream effects.

Since it's such a useful marker for inflammasome activation, ASC oligomerization is measured by researchers studying inflammatory response, often using Western blot or other techniques.