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:

Inhibition of transcription factors belonging to the rel / NF-kappa B family by a transdominant negative mutant. The KBF1 factor, which binds to the enhancer A located in the promoter of the mouse MHC class I gene H-2Kb, is indistinguishable from the p50 DNA binding subunit of the transcription factor NF-kappa B, which regulates a series of genes involved in immune and inflammatory responses. The KBF1 / p50 factor binds as a homodimer but can also form heterodimers with the products of other members of the same family, like the c-rel and v-rel (proto) oncogenes. The dimerization domain of KBF1 / p50 is contained between amino acids 201 and 367. A mutant of KBF1 / p50 (delta SP), unable to bind to DNA but able to form homo-or heterodimers, has been constructed. This protein reduces or abolishes in vitro the DNA binding activity of wild-type proteins of the same family (KBF1 / p50, c-and v-rel). This mutant also functions in vivo as a trans-acting dominant negative regulator: the transcriptional inducibility of the HIV long terminal repeat (which contains two potential NF-kappa B binding sites) by phorbol ester (PMA) is inhibited when it is co-transfected into CD4 + T cells with the delta SP mutant. Similarly the basal as well as TNF or IL1-induced activity of the MHC class I H-2Kb promoter can be inhibited by this mutant in two different cell lines. These results constitute the first formal demonstration that these genes are regulated by members of the rel / NF-kappa B family.
{"CellLine": ["cell lines", "CD4 + T cells"], "CellType": [], "DNA": ["H - 2Kb", "mouse MHC class I gene", "promoter", "c - rel and v - rel (proto) oncogenes", "HIV long terminal repeat", "enhancer A", "MHC class I H - 2Kb promoter"], "Protein": ["p50 DNA binding subunit", "heterodimers", "TNF", "wild - type proteins", "trans - acting dominant negative regulator", "dimerization domain", "between amino acids 201 and 367", "transcription factor NF - kappa B", "KBF1 factor", "delta SP", "c - and v - rel", "rel / NF - kappa B family", "KBF1 / p50 factor", "NF - kappa B", "transdominant negative mutant", "KBF1 / p50", "homodimer", "transcription factors"], "RNA": []}