Q: 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 cathepsin D serum levels a valid serum marker in renal cell carcinoma?
Answer: In contrast to overexpression of Cath D in primary RCC tissue, serum Cath D is not altered in RCC patients when compared with healthy volunteers. In this small cohort, Cath D serum levels did not reveal additional clinical information in patients diagnosed with a small renal mass. Further prospective multicenter studies might shed more light on the value of Cath D in the diagnostics of RCC.
A:
no