instruction:
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:
Question: Are the receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus downregulated in productively infected cells?
Answer: A-MLV or GALV receptors remain on the surface of chronically infected cells and are detectable by respective antibodies, indicating that these receptors are not downregulated in these infected cells as previously proposed. We were also able to detect viral envelope proteins on the infected cell surface and infected cells are unable to bind soluble A-MLV or GALV envelopes indicating that receptor binding sites are masked by endogenously expressed A-MLV or GALV viral envelope. However, receptor masking does not completely prevent A-MLV or GALV superinfection.
answer:
no


question:
Question: Does the ets-domain transcription factor Spdef promote maturation of goblet and paneth cells in the intestinal epithelium?
Answer: Spdef acts downstream of Math1 to promote terminal differentiation of a secretory progenitor pool into Paneth and goblet cells.
answer:
yes


question:
Question: Do the reasons students choose to undertake a nursing degree?
Answer: Nursing remains a career of choice for young and mature students entering university. It is seen to provide security, interest and opportunity to help and care for others. Universities must focus on this as they develop programmes for a generation where multiple changes of career appear inevitable during their lifetime. The nursing profession needs to look at career pathways after graduation that provide these challenges within nursing itself.
answer:

yes