TTLL8 (tubulin tyrosine ligase-like 8) is a protein-glycine ligase that catalyzes tubulin polyglycylation, a posttranslational modification of microtubules 1. This modification is essential for proper axoneme structure and flagellar function, particularly in sperm motility 1. TTLL8 functions as a tubulin glycine ligase involved in primary cilia formation and maintenance 2, which plays a critical role in controlling cell proliferation in epithelial tissues. Disease relevance includes colorectal cancer, where reduced TTLL3/TTLL8 expression correlates with increased cell proliferation and tumor development 2. Additionally, TTLL8 has emerged as an immunogenic tumor-associated antigen in high-grade serous ovarian cancer, where it is expressed in 56.7% of cases and associated with worse overall prognosis 3. Clinically, TTLL8 represents a potential target for antigen-targeted immunotherapy in ovarian cancer, as antigen-specific CD8 T cell responses can trigger cancer cell killing 3. Pharmacologically, TTLL8 activity can be inhibited by phosphinic acid-based compounds in the low micromolar range 1, suggesting therapeutic potential in modulating ciliary function or cancer immunity.