You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

The Tumor Suppressor Kruppel-Like Factor 6 is a Novel Aryl Hydrocarbon Receptor DNA Binding Partner. The Aryl Hydrocarbon Receptor (AhR) is a ligand mediated basic helix-loop-helix transcription factor of Per/Arnt/Sim family that regulates adaptive and toxic responses to variety of chemical pollutants including polycyclic aromatic hydrocarbons (PAH) and halogenated aromatic hydrocarbons, most notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Ligand activation leads to AhR nuclear translocation and binding to a xenobiotic response element (XRE) in association with the aryl receptor nuclear translocator (Arnt) to regulate gene expression. Several recent genome-wide transcriptional studies identified numerous AhR target genes that lack the canonical XRE recognition site in the promoter regions. Characterization of one such target gene, the Plasminogen Activator Inhibitor 1 (PAI-1) identified a novel non-consensus XRE (NC-XRE) that confers TCDD responsiveness independently of the Arnt protein. Studies reported here show that the NC-XRE is a recognition site for the AhR and a new binding partner, the Kruppel-like Factor (KLF) family member KLF6. In vivo chromatin immunoprecipitations and in vitro DNA binding studies demonstrate that the AhR and KLF6 proteins form an obligatory heterodimer necessary for NC-XRE binding. Mutational analyzes show that the protein-protein interactions involve the AhR C-terminus and KLF6 N-terminus, respectively. Moreover, NC-XRE binding depends on the 5' basic region in KLF6 rather than the previously characterized zinc finger DNA binding domain. Collectively, the results unmask a novel AhR signaling mechanism distinct from the canonical XRE-driven process that will enrich our future understanding of AhR biology.
{"Chemical": ["zinc", "Aryl Hydrocarbon", "polycyclic aromatic hydrocarbons", "PAH", "2,3,7,8-tetrachlorodibenzo-p-dioxin", "halogenated aromatic hydrocarbons", "TCDD"]}