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:

Cloning of murine TCF-1, a T cell-specific transcription factor interacting with functional motifs in the CD3-epsilon and T cell receptor alpha enhancers. CD3-epsilon gene expression is confined to the T cell lineage. We have recently identified and cloned a human transcription factor, TCF-1, that binds to a functional element in the T lymphocyte-specific enhancer of CD3-epsilon. In a panel of human cell lines, TCF-1 expression was restricted to T lineage cells. TCF-1 belonged to a novel family of genes that contain the so-called high mobility group 1 (HMG) box. Here we report the cloning of murine TCF-1. Two splice alternatives were identified that were not previously observed in human TCF-1. Murine and human TCF-1 displayed a 95. 5% overall amino acid homology. Recombinant murine and human TCF-1 recognized the same sequence motif in the CD3-epsilon enhancer as judged by gel retardation and methylation interference assays. With the murine cDNA clones several aspects of TCF-1 were analyzed. First, deletion analysis revealed that a region of TCF-1 containing the HMG box was sufficient for sequence-specific binding. Second, by high stringency Northern blotting and in situ hybridization, TCF-1 expression was shown to be confined to the thymus and to the T cell areas of the spleen. Third, TCF-1 bound specifically to a functional T cell-specific element in the T cell receptor alpha (TCR-alpha) enhancer. The T lineage-specific expression and the affinity for functional motifs in the TCR-alpha and CD3-epsilon enhancers imply an important role for TCF-1 in the establishment of the mature T cell phenotype.
{"CellLine": ["T cell lineage"], "CellType": ["mature T cell phenotype", "T lineage cells"], "DNA": ["functional motifs", "CD3 - epsilon enhancer", "the TCR - alpha", "mobility group 1 (HMG) box", "murine cDNA clones", "TCR - alpha and CD3 - epsilon enhancers", "HMG box", "the T cell receptor alpha (TCR - alpha) enhancer", "T cell - specific element", "T cell receptor alpha (TCR - alpha) enhancer", "CD3 - epsilon and T cell receptor alpha enhancers"], "Protein": ["Murine and human TCF - 1", "murine TCF - 1", "human transcription factor", "transcription factor", "Recombinant murine and human TCF - 1", "human TCF - 1", "TCF - 1", "CD3"], "RNA": []}