What is the largest known structure in the universe?

The Hercules–Corona Borealis Great Wall (HCB) or simply the Great Wall or the Great Gamma-Ray Burst Wall is a putative galaxy filament that, if confirmed, would be one of the largest known structures in the observable universe, measuring approximately 10 billion light-years in length, or ~10.8% the length of the observable universe. This massive superstructure is a region of the sky seen in the data set mapping of gamma-ray bursts (GRBs) that has been found to have a concentration of similarly distanced GRBs that is unusually higher than the expected average distribution. It was discovered in early November 2013 by a team of American and Hungarian astronomers led by István Horváth, Jon Hakkila and Zsolt Bagoly while analyzing data from the Swift Gamma-Ray Burst Mission, together with other data from ground-based telescopes. If confirmed, it would exceed the size of the possible Huge-LQG by about a factor of two.