Given the task definition and input, reply with output. 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.

Question: Are thymidylate synthase and folyl-polyglutamate synthase clinically useful markers of response to pemetrexed in patients with malignant pleural mesothelioma?
Answer: Although previous retrospective data suggest that TS and FPGS expression might be potential markers of Pem efficacy in MPM, our data indicate these markers lack sufficient predictive value in individual patients and should not be used to guide therapeutic decisions in the absence of prospective studies.
no