FAM8A1 (family with sequence similarity 8 member A1) is a conserved cofactor protein localized to chromosome 6 that plays a critical role in endoplasmic reticulum-associated degradation (ERAD), a ubiquitin-proteasome-dependent quality control pathway 1. The protein functions as an essential component of the HRD1 ubiquitin ligase complex, where it promotes complex assembly through evolutionarily conserved cytoplasmic domain interactions 1. Specifically, FAM8A1 engages the HAF-H domain of Hrd1 and facilitates binding of the cofactor Herp to Hrd1, interactions required for ERAD machinery functionality 1. FAM8A1 expression oscillates under circadian clock control alongside other ERQC components, suggesting temporal regulation of protein quality control 2. Disease relevance is demonstrated by a FAM8A1 frameshift variant associated with REM sleep behavior disorder, urinary retention, and mydriasis in Russian Blue cats, indicating the protein's importance in nervous system homeostasis 3. Additionally, FAM8A1 downregulation occurs in chr6 obstructive pulmonary disease through EGF/ERBB2-mediated epigenetic silencing, promoting endoplasmic reticulum stress and disease progression 4. FAM8A1 expression also correlates with metabolic outcomes following bariatric surgery in type 2 diabetes patients 5. These findings establish FAM8A1 as a functionally important ERAD component with implications for neurodegenerative, respiratory, and metabolic diseases.