What is the best way to cite NCBI data for my paper?
The way to cite NCBI databases, services, and data is described by NCBI itself in an "NCBI Knowledgebase" post here: https://support.nlm.nih.gov/knowledgebase/article/KA-03391/en-us

In addition, NCBI provides a separate file with lots of examples:  ftp://ftp.ncbi.nlm.nih.gov/pub/education/supportcenter/NCBI_services_citation_examples.txt 

Don't guess, look it up !

(Archived permalink: https://web.archive.org/web/20181028213653/https://support.nlm.nih.gov/knowledgebase/article/KA-03391/en-us)