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: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. 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:

Frequency of the GPR7 Tyr135Phe allelic variant in lean and obese subjects. Background: GPR7, the endogenous coupled receptor for neuropeptide B and neuropeptide W, is expressed in several regions of the Central Nervous System (CNS), which are involved in the regulation of feeding behaviour. GPR7 affects the regulation of energy balance through a mechanism independent of leptin and melanocortin pathways. Aim: Aim of this study was to investigate whether GPR7 gene mutations can be detected in human subjects and, in that event, if they are differently distributed among lean and obese subjects. Subjects and Methods: The coding region of GPR7 were sequenced in 150 obese patients and 100 normal-weight unrelated controls. Functional studies of the allelic variants were performed. Results: One genetic GPR7 variant was found (Tyr135Phe - rs33977775) in obese subjects (13,3%) and lean control (25%). Functional studies did not reveal significant differences between the wild type and the Tyr135Phe allelic variants in their NPW mediated capacity to inhibit forskolin-induced cAMP production. Conclusions: Screening of GPR7 gene mutations among lean and obese subjects revealed a Tyr135Phe allelic variant that was fairly common in the study population. As indicated by in vitro and in silico studies, this variant is unlikely to cause a functional derangement of the receptor.
{"Chemical": ["forskolin", "cAMP"]}