SetDB1 is best known as a chromatin modifier catalyzing H3K9me3. However, recent studies show that SetDB1 can mediate H3K27me3-deposition by PRC2, CTCF-binding, recruit DNA methyltransferases, and potentially regulate additional chromatin processes. To gain further insights, we profiled the protein interactome of SetDB1, using a HeLa cell model (BAC clone, PMID 18391959) in which a GFP-tagged SetDB1 is endogenously expressed, closely mimicking the native microenvironment of SetDB1. The GFP tag provides for efficient pulldown using GFP nanobodies fused to agarose beads.