First, the sample was relatively small, and so the reported results need to be validated in a larger sample; Second, the study subjects were drawn from a northern Chinese population, and similar studies in other populations were needed to confirm our findings; Third, we selected one SNP (rs7208480) that was found to be associated with PH by a literature search, without studying all the SNPs of ADORA2B [35]; Finally, the functional relevance of the identified polymorphisms in CHF remains to be determined. This evidence concerns the gene ADORA2B and congestive heart failure.