Clusters found with your TF of interest:

Not all of these will be good Discoveries; and not all will be good matches to your motif of interest. Be sure to check out the e-values in each case (shown in the table below). It can also be the case that other motifs are better matches. This is just giving you a table of possibilities.
clusterTFSiteseDiscoveryeMatchdatabase
455Arnt702.6e-260.00084169JASPAR
390Arnt474.1e-260.00065449JASPAR
292Arnt944.9e-210.02595JASPAR
23Arnt554.7e-180.00037684JASPAR
1027Arnt440.00000000000550.00013651JASPAR
2277Arnt270.0000130.0049381JASPAR
2105Arnt230.00110.0096683JASPAR