I have Google Adsense in 4 of my websites.

When using The Sites report, (Performance reports, Sites) A good 20% of my ads are served from the domain pubads.g.doubleclick.net.

I am trying to figure out what this is.

I assume it is coming from one of these 2 but not sure?

I use DFP to serve ads and Adsense is allowed to compete with my Line Items.

I use other ad networks which default to Google Adsense when they don't have any ads to display.

Any ideas would be appreciated. thanks