The Diffuse Gamma-Ray Background (DGRB) collects the radiation produced by all those sources that are not bright enough to be resolved individually. Therefore, it represents an essential tool to study faint gamma-ray emitters, like star-forming or radio galaxies and the exotic Dark Matter. The anisotropy pattern of the DGRB is extremely informative: I will review the recent measurement of the anisotropy angular power spectrum performed by the Fermi LAT Collaboration with almost 80 months of data. This brand-new result can be used to infer the composition of the DGRB. In particular, I will show how it constrains the emission expected from Dark Matter.