ZNRD2 (zinc ribbon domain containing 2) is a multi-functional protein with primary roles in protein quality control and viral restriction. Its primary function involves serving as an adaptor protein that recruits the E3 ubiquitin ligase HERC2 to recognize orphaned subunits of the cytosolic chaperonin CCT, facilitating their selective ubiquitination and degradation 1. This recognition mechanism is essential for assembly quality control, as orphan subunits represent a major source of cellular quality control substrates 1. Structurally, ZNRD2 contains a zinc ribbon domain (ZNRD2) and functions as a Tankyrase 1 binding partner through its C-terminal domain, which additionally serves as a nuclear export signal 2. Beyond quality control, ZNRD2 acts as a host restriction factor against respiratory syncytial virus (RSV) by promoting aggregation and insolubility of RSV nucleoprotein, thereby impairing viral replication 3. However, RSV phosphoprotein antagonizes this antiviral function by maintaining viral nucleoprotein in monomeric form, creating a dynamic virus-host interaction 3. ZNRD2's centromere association and role in mitosis suggest additional functions in cell cycle regulation, and its identification as an autoantigen in Sjögren's syndrome and scleroderma indicates potential clinical relevance in autoimmune diseases 2.