FAM98B is an accessory subunit of the human tRNA-splicing ligase complex (tRNA-LC) that functions in mature tRNA generation 1. As a component of this five-subunit complex alongside RTCB, DDX1, CGI-99, and Ashwin, FAM98B contributes to joining spliced tRNA halves by incorporating splice junction phosphates into mature tRNAs 1. The protein contains a highly glycine-rich intrinsically disordered region (IDR) that serves as its primary functional domain 2. Beyond tRNA splicing, FAM98B participates in a broader RNA metabolism complex with DDX1 and C14orf166 that shuttles between nucleus and cytoplasm in a transcription-dependent manner 3. FAM98B may possess broad substrate specificity and function toward additional RNAs beyond tRNA 4. Clinically, FAM98B depletion through polyglycine aggregation in GGC repeat disorders causes progressive motor coordination deficits and hindbrain pathology in mice, with patient tissues showing aberrant tRNA splicing intermediates 2. FAM98B also regulates PRMT1 expression and correlates with colorectal cancer progression 5. Additionally, FAM98B functions in osteoclast lysosome trafficking and bone resorption 6, indicating roles beyond RNA metabolism.