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:

Gemcitabine and pemetrexed disodium combinations in vitro and in vivo.
Pemetrexed disodium (ALIMTA) is a novel antimetabolite that inhibits at least three folate-dependent enzymes, thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. Pemetrexed disodium is broadly active in a wide variety of solid tumours, including non-small cell lung, breast, bladder, head and neck and ovarian cancers. Gemcitabine is a broadly active pyrimidine nucleoside antimetabolite, which is approved for the treatment of pancreatic and non-small cell lung cancers. Three preclinical studies have been reported that show cytotoxic synergy between gemcitabine and pemetrexed. Clinical activity with this combination has been observed in a phase I study, with partial responses in three of five patients previously treated for non-small cell lung cancer. An international phase II study of this combination in non-small cell lung cancer is ongoing.
{"Chemical": ["thymidylate", "pemetrexed", "glycinamide ribonucleotide", "gemcitabine", "Pemetrexed disodium", "dihydrofolate", "pemetrexed disodium", "pyrimidine nucleoside", "folate", "ALIMTA", "Gemcitabine"], "Protein": ["dihydrofolate reductase", "glycinamide ribonucleotide formyltransferase", "thymidylate synthase"]}