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.

Example Input: Question: Are mutational status of KIT and PDGFRA and expression of PDGFRA associated with prognosis after curative resection of primary gastrointestinal stromal tumors ( GISTs )?
Answer: Our data do not support the notion that expression of PDGFRA or mutations in KIT or PDGFRA are independent prognostic factors after curative resection of primary GIST.
Example Output: no

Example Input: Question: Is pre-surgical cortical activation to food pictures associated with weight loss following bariatric surgery?
Answer: We found that neural activity in previously established regions associated with cognitive and behavioral self-regulation predicts weight loss following bariatric surgery. These preliminary findings highlight the role of neural circuitry in the success and maintenance of weight loss and suggest a possible future use of fMRI in screening LAGB surgery candidates.
Example Output: yes

Example Input: Question: Does elevated elafin/trappin-2 in the female genital tract is associate with protection against HIV acquisition?
Answer: Using a unique proteomics approach in a large scale, cross-sectional cohort study, we identified elafin/trappin-2 as a novel innate immune factor, which is highly associated with resistance. This association was confirmed within an independent, prospective cohort study. Genital tract elafin/trappin-2 levels constitute a natural correlate of HIV protection in humans.
Example Output:
yes