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: ["Protein", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Dexamethasone", ...], "Protein" : ["BRCA-1", ...]}. 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:

Discovery of a series of novel 5H-pyrrolo[2,3-b]pyrazine-2-phenyl ethers, as potent JAK3 kinase inhibitors.
We report the discovery of a novel series of ATP-competitive Janus kinase 3 (JAK3) inhibitors based on the 5H-pyrrolo[2,3-b]pyrazine scaffold. The initial leads in this series, compounds 1a and 1h, showed promising potencies, but a lack of selectivity against other isoforms in the JAK family. Computational and crystallographic analysis suggested that the phenyl ether moiety possessed a favorable vector to achieve selectivity. Exploration of this vector resulted in the identification of 12b and 12d, as potent JAK3 inhibitors, demonstrating improved JAK family and kinase selectivity.
{"Chemical": ["5H-pyrrolo[2,3-b]pyrazine", "ATP", "5H-pyrrolo[2,3-b]pyrazine-2-phenyl ethers"], "Protein": ["JAK", "Janus kinase 3", "kinase", "JAK3"]}