Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.
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Question: Question: Are common genetic variants related to vitamin D status associated with esophageal squamous cell carcinoma risk in China?
Answer: Our results suggested that common genetic variants related to vitamin D levels are not associated with risk of ESCC in this Chinese population.

Answer: no

Question: Question: Is central venous saturation an alternative to mixed venous saturation during cardiopulmonary bypass in coronary artery surgery patients?
Answer: Although mean biases between the measurements were low, limits of agreement were too large to provide a clinically acceptable estimation of SvO(2) by ScvO(2) in these conditions. Variations in regional oxygen consumption seem to be the main factor worsening the relationship.

Answer: no

Question: Question: Does blood presence of circulating oncofetal fibronectin mRNA , by RT-PCR , represent a useful specific marker for the management and follow-up of thyroid cancer patients?
Answer: We underline how the complexity of onfFN transcripts could affect the RT-PCR procedure. In addition, the presence of onfFN transcripts in several normal and cancer tissues, along with non-thyroid biological fluids or cells, does not allow the use of this marker for cancer monitoring.

Answer:
no