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:

Estramustine binding protein in primary tumours and metastases of malignant melanoma.
The presence of estramustine binding protein (EMBP), a 54 kD cytosolic glycoprotein, which is distinct from the estrogen receptor, was investigated in a pilot study of primary malignant melanomas and their metastases. In 11 primary melanomas EMBP was demonstrated by immunohistochemistry. The percentage of positive melanoma cells ranged between 11-91% with a mean of 57%. Radioimmunoassay on metastatic tissue revealed significant amounts of EMBP, with values ranging between 0.6-4.2 with a mean of 1.6 ng/mg protein. A high number of cells with a positive stain for EMBP in the primary tumours was significantly correlated to a short interval between diagnosis and the occurrence of metastases. Presence of EMBP in malignant melanoma may have prognostic significance and the role of hormone-linked cytostatic drugs in the treatment of this disease needs further investigation.
{"Chemical": ["estrogen", "Estramustine", "estramustine"], "Protein": ["EMBP", "Estramustine binding protein", "estrogen receptor", "estramustine binding protein"]}