FAF2 (Fas-associated factor family member 2) is a bifunctional ubiquitin-regulatory adaptor protein with diverse roles in protein quality control and organellar homeostasis. Structurally, FAF2 functions as a VCP/p97 cofactor through its UBX domain to facilitate ubiquitin-dependent protein extraction and degradation 12. Primarily, FAF2 mediates endoplasmic reticulum-associated degradation (ERAD) of misfolded proteins and regulates stress granule disassembly by promoting ubiquitinated G3BP1 extraction via VCP engagement 1. FAF2 maintains peroxisomal homeostasis by extracting ubiquitylated peroxisomal membrane proteins like PMP70, thereby preventing excessive pexophagy under steady-state conditions 23. Metabolically, FAF2 inhibits lipid droplet degradation through PNPL2 inhibition and regulates saturated fatty acid responses via peroxisomal ether lipid synthesis 45. FAF2 also modulates cholesterol-dependent mTORC1 signaling through ER-lysosome contacts 6. Clinically relevant, FAF2 elevation associates with alcohol-associated liver disease; its knockdown reduces hepatic steatosis by enhancing lipolysis and upregulating PCSK9 pathways 7. Additionally, targeted FAF2 delivery suppresses tau aggregation and ameliorates neurodegeneration in tau pathology models 8, suggesting therapeutic potential in metabolic and neurodegenerative diseases.