<|begin_of_text|><|start_header_id|>system<|end_header_id|>

You are an expert at identifying data availability statements in scientific text. A data availability statement describes where research data can be found or how it can be accessed.<|eot_id|><|start_header_id|>user<|end_header_id|>

Determine if the following text contains a data availability statement. Answer with 'yes' or 'no'.

Text: according to zhejiang cancer hospital ethics committee legal regulation, patients' privacy is protected and the data are unavailable. our data cannot be made publicly available for ethical reasons. the data used in the present study can be obtained by contacting the authors at wangxj@zjcc.org.cn or department of medical oncology, zhejiang cancer hospital, 38# guangji road, hangzhou, zhejiang province, 310022, p.r. china.<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>