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: ["RNA", "CellLine", "Protein", "DNA", "CellType"].

Please return the output as a JSON object of the format: {"DNA" : ["TAL1", ...], "RNA": ["mRNAs", ...], "CellLine": ["T cells", ...], "CellType": ["monocytes", ...], "Protein": ["IL-2", ...]}. 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:

Mutations in the Pit-1 gene in children with combined pituitary hormone deficiency. Pit-1 is a pituitary-specific transcription factor that binds to and transactivates promoters of growth hormone and prolactin genes. In three unrelated Japanese children with combined pituitary hormone deficiency, we identified three point mutations in the Pit-1 gene, Pro24Leu, Arg143Gln, and Arg271Trp, located on the major transactivation region, POU-specific domain, and POU-homeodomain, respectively.
{"CellLine": [], "CellType": [], "DNA": ["POU - specific domain", "Pit - 1 gene", "major transactivation region", "promoters", "POU - homeodomain", "growth hormone and prolactin genes", "Pro24Leu", "Arg143Gln", "Arg271Trp"], "Protein": ["Pit - 1", "pituitary - specific transcription factor"], "RNA": []}