The National Center for Biotechnology Information (NCBI) provides a wide range of online resources for biological information and data, including GenBank, PubMed, and various databases for genes, proteins, and chemicals. These resources are accessible through the NCBI home page at http://www.ncbi.nlm.nih.gov. The Entrez system allows users to search and retrieve data from these databases. Custom implementations of BLAST are used for specialized searches. Recent developments include the Variation Viewer, PubMed Commons, BLAST in the cloud, and Entrez Direct. The NCBI Guide serves as an interactive directory of resources. The Entrez databases include 40 diverse databases with over 1.3 billion records. The NCBI also maintains several databases for medical genetics, such as ClinVar, GTR, and MedGen. Other resources include the RefSeq database, the Sequence Read Archive, and the BioSample database. The NCBI also provides tools for protein analysis, such as the Protein Clusters database and the HIV-1/Human Protein Interaction Database. The NCBI maintains databases for genomic sequences, including the Genome Reference Consortium (GRC) and the BioProject database. The NCBI also provides resources for chemical and bioassay data, such as PubChem. The NCBI offers various tools for gene expression, including the Gene Expression Omnibus (GEO) and UniGene. The NCBI also provides resources for genetic variation, including dbSNP, dbVar, and dbGaP. The NCBI maintains databases for clinical genetics, such as dbMHC, dbLRC, and dbRBC. The NCBI provides a variety of tools for sequence analysis, including BLAST, COBALT, and IgBLAST. The NCBI also provides resources for genome sequencing, including the Genome database and the Assembly database. The NCBI maintains a variety of databases for biological systems, including Biosystems and the Pathway Interaction Database. The NCBI provides resources for influenza genome data and for epigenomics. The NCBI also provides resources for genetic and medical research, including the dbGaP database and the dbVar database. The NCBI provides a variety of tools for data analysis, including the E-Utilities and the Entrez Programming Utilities. The NCBI also provides resources for educational and outreach initiatives, including webinars, tutorials, and the NCBI YouTube channel. The NCBI provides a variety of tools for data retrieval and analysis, including the E-Utilities and the Entrez system. The NCBI provides a variety of resources for data sharing and collaboration, including the PubMed Central (PMC) database and the NCBI Bookshelf. The NCBI provides a variety of resources for data access and retrieval, including the NCBI FTP site and the Entrez system. The NCBI provides a variety of resources for data analysis and interpretation, including the E-Utilities and the Entrez system. The NCBI provides a variety of resources for data sharing and collaboration, includingThe National Center for Biotechnology Information (NCBI) provides a wide range of online resources for biological information and data, including GenBank, PubMed, and various databases for genes, proteins, and chemicals. These resources are accessible through the NCBI home page at http://www.ncbi.nlm.nih.gov. The Entrez system allows users to search and retrieve data from these databases. Custom implementations of BLAST are used for specialized searches. Recent developments include the Variation Viewer, PubMed Commons, BLAST in the cloud, and Entrez Direct. The NCBI Guide serves as an interactive directory of resources. The Entrez databases include 40 diverse databases with over 1.3 billion records. The NCBI also maintains several databases for medical genetics, such as ClinVar, GTR, and MedGen. Other resources include the RefSeq database, the Sequence Read Archive, and the BioSample database. The NCBI also provides tools for protein analysis, such as the Protein Clusters database and the HIV-1/Human Protein Interaction Database. The NCBI maintains databases for genomic sequences, including the Genome Reference Consortium (GRC) and the BioProject database. The NCBI also provides resources for chemical and bioassay data, such as PubChem. The NCBI offers various tools for gene expression, including the Gene Expression Omnibus (GEO) and UniGene. The NCBI also provides resources for genetic variation, including dbSNP, dbVar, and dbGaP. The NCBI maintains databases for clinical genetics, such as dbMHC, dbLRC, and dbRBC. The NCBI provides a variety of tools for sequence analysis, including BLAST, COBALT, and IgBLAST. The NCBI also provides resources for genome sequencing, including the Genome database and the Assembly database. The NCBI maintains a variety of databases for biological systems, including Biosystems and the Pathway Interaction Database. The NCBI provides resources for influenza genome data and for epigenomics. The NCBI also provides resources for genetic and medical research, including the dbGaP database and the dbVar database. The NCBI provides a variety of tools for data analysis, including the E-Utilities and the Entrez Programming Utilities. The NCBI also provides resources for educational and outreach initiatives, including webinars, tutorials, and the NCBI YouTube channel. The NCBI provides a variety of tools for data retrieval and analysis, including the E-Utilities and the Entrez system. The NCBI provides a variety of resources for data sharing and collaboration, including the PubMed Central (PMC) database and the NCBI Bookshelf. The NCBI provides a variety of resources for data access and retrieval, including the NCBI FTP site and the Entrez system. The NCBI provides a variety of resources for data analysis and interpretation, including the E-Utilities and the Entrez system. The NCBI provides a variety of resources for data sharing and collaboration, including