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 cognitive-behavioral phenotypes of Williams syndrome associated with genetic variation in the GTF2I gene , in a healthy population?
Answer: These findings implicate the GTF2I gene in the neurogenetic basis of social communication and social anxiety, both in Williams syndrome and among individuals in healthy populations.
yes

Question: Are decreased plasma levels of select very long chain ceramide species associated with the development of nephropathy in type 1 diabetes?
Answer: These studies demonstrate, prospectively, that decreased plasma levels of select ceramide species are associated with the development of macroalbuminuria in type 1 diabetes.
yes

Question: Is γ-Glutamyltranspeptidase a prognostic marker of survival and recurrence in radiofrequency-ablation treatment of hepatocellular carcinoma?
Answer: Serum GGT is a convenient prognostic biomarker related to OS and recurrence in HCC patients undergoing RFA treatment.

yes