The NOPdb is a comprehensive database that archives data on over 700 proteins identified by mass spectrometry analyses from human nucleoli. This database provides a valuable resource for researchers to study the nucleolar proteome, its functions, and its role in various cellular processes. By analyzing the NOPdb, researchers can gain insights into the molecular mechanisms underlying nucleolar function and its dysregulation in diseases. The database is a crucial tool for understanding the complex interactions between nucleolar proteins and their impact on cellular behavior.