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:

The zinc finger transcription factor Egr-1 is essential for and restricts differentiation along the macrophage lineage. We have isolated cDNA clones of myeloid differentiation primary response (MyD) genes, activated in the absence of de novo protein synthesis following induction for differentiation along either the macrophage or granulocyte lineage in human myeloblastic leukemia HL-60 cells. One cDNA clone of a primary response gene, expressed upon macrophage differentiation, encoded for Egr-1, a zinc finger transcription factor. The Egr-1 gene was observed to be transcriptionally silent in HL-60 cells, but active in U-937 and M1 cells, the latter two being predetermined for macrophage differentiation. Egr-1 antisense oligomers in the culture media blocked macrophage differentiation in both myeloid leukemia cell lines and normal myeloblasts. HL-60 cells constitutively expressing an Egr-1 transgene (HL-60Egr-1) could be induced for macrophage, but not granulocyte, differentiation. These observations indicate that expression of Egr-1 is essential for and restricts differentiation of myeloblasts along the macrophage lineage.
{"CellLine": ["M1 cells", "myeloblastic leukemia HL - 60 cells", "HL - 60 cells", "U - 937", "myeloid leukemia cell lines"], "CellType": ["granulocyte", "myeloblasts", "granulocyte lineage", "macrophage", "macrophage lineage"], "DNA": ["Egr - 1 transgene", "Egr - 1 gene", "cDNA clone", "HL - 60Egr - 1", "myeloid differentiation primary response (MyD) genes", "cDNA clones"], "Protein": ["zinc finger transcription factor", "Egr - 1", "zinc finger"], "RNA": []}